A double homicide occurs that involves infidelity; McGarrett and the team share disastrous Valentine's Day experiences.

While McGarrett and Danno celebrate Valentine's Day with their girlfriends, the Five-0 team investigates the murder of a man taking a class on how to meet women.

On Valentine's Day, Tani and Noelani are held hostage during a convenience store robbery; the team investigates the murder of a Thai diplomat whose wife confesses to the crime, but Danny suspects she's covering for the real killer.

MacGyver uses a heater and hot sauce to help a key presidential candidate in Ecuador receive a heart transplant he desperately needs after a rebel group tries to sabotage delivery of the organ.

MacGyver and Jack "steal" a priceless painting to draw out an infamous stolen art dealer; Riley's estranged father asks to be part of her life; Matty sends Bozer to a spy training camp.

Mac and the team follow mercenaries who are transporting stolen lethal nerve gas; Jack confronts Elwood about Riley; Bozer is pushed to his limit in spy school.

Mac must help college students stranded on a research ship in the Arctic Ocean; Jack kidnaps Elwood to find out what he's up to; Bozer's feelings toward Leanna grow stronger.

The LAPD interrupts the team's Christmas celebration to arrest Mac for terrorism when they find a body in a building destroyed by a bomb Mac built.

When Mac's nemesis rigs Mac's house with explosives and traps him and Jack inside, Mac uses a karaoke mic and an audio transformer to let the team know that the bomb is a distraction for a bigger one.

Mac participates in a challenge to create robotic combat machines; Mac must help a competitor when her vehicle is hacked and heads for the Pentagon; Jack attends his high school reunion.

The team heads to New Orleans to track down a con artist posing as the wife of one of Jack's old CIA aliases; enemies of his old alias resurface looking for revenge.

The members of the BAU team are brought back to their origins as they look at one of Gideon and Rossi's old cases.

When a hero emerges from the wreckage of an explosion in Indianapolis, the BAU team members must protect him as they try to identify the person responsible before more bombings occur.

The members of the BAU team search for a suspect who may have witnessed abuse as a child; Kate is worried when her niece and a friend make plans with a boy they met online.

When two guards at a maximum security prison are murdered, the BAU team thinks one or more people within the prison walls may be responsible.

The BAU tracks a serial killer in Wisconsin; Kate is faced with trouble when her niece, Meg, starts acting out.

When an up-and-coming congressman's wife disappears, the team investigates his political enemies as potential suspects.

International Unit Chief Jack Garrett (Gary Sinise) and his team requires assistance from the BAU when a family of four is abducted during their Barbados vacation.

When the members of a family are found murdered at their dining room table, the team looks for secrets in their past; Hotch tries to make peace with his father-in-law (Ed Asner).

When three alleged murderers claim that they were attacked by a monster at the moment of the crimes, the BAU searches for a suspect who controls minds; the hunt puts one team member in danger.

The BAU tracks a vigilante in Los Angeles who is shooting people with possible ties to criminal activity.

The team suspects Kate's niece and her friend were kidnapped by an online predator involved in sex trafficking and race to find them before they are hurt.

The BAU interviews candidates to take the opening left by Kate's departure; the team tracks a serial killer who leaves behind evidence that indicates a person intent on revenge.

The team must find the person responsible for a sarin gas attack on a Los Angeles bus before a larger incident occurs.

The team suspects a jilted unknown subject is responsible when brides are murdered on the eve of their nuptials.

When a robbery-homicide leaves three restaurant employees dead, a cold case that occurred in the same town six years earlier could yield a lead.

A notorious street artist becomes a suspect when corpses are used in macabre graffiti art in Detroit; Dr. Lewis tries to balance work and her relationship with her fiance.

All evidence points to the film distributor, who also happens to be a registered sex offender, in the investigation of an adult film star's murder, but an accident at the lab may taint a key piece of evidence.

When a man is murdered as he tries to pay his son's ransom with $3 million worth of jewels, the CSI team is called to investigate and one member of the group is killed in the line of duty.

A drive-by shooting from a boat leaves a beach partier dead, and the CSI team protects the 8-year-old witness during the search for the killer.

When a young woman is pushed in front of a moving bus, the CSI team suspects her boyfriend; Calleigh's father fears he may have killed someone after a night of drinking.

After students use e-mails and text messages to organize a spontaneous gathering at a golf course, the body of a high-school senior is found.

The CSI team tracks the killer of an 18-year-old woman, an investigative aide for Alcohol Beverage Control who was monitoring underage drinking when she was murdered at a hip Miami nightclub.

The wife of a famous Miami ballplayer is found murdered in her home, and her philandering husband is the prime suspect until his corpse is found in the house too.

As a tidal wave heads toward Miami, Horatio and the team must stop a gang of bank robbers who are trying to take advantage of the natural disaster.

A man is found dead after an evening of speed-dating, and detectives immediately suspect one of his dates, but the focus changes when the team learns the victim witnessed an assault.

The team probes modern-day piracy after six bodies are found off the coast of Miami.

The team delves into the complicated personal lives of members of Miami's judicial community after a man, in possession of a sexy DVD featuring a criminal judge, falls from a building, killing a pedestrian.

A brutal carjacking turns into murder, and the team learns that the victim had a gambling problem that could have bankrupted the family business; Alexx hires a body hauler and must investigate when he is accused of stealing from the dead.

The team investigates when a stockbroker -- who moonlights as a stripper -- is murdered; after a 24-year absence, Booth's mother (Joanna Cassidy) shows up with a request.

The team tries to prevent a viral outbreak during an investigation into a journalist's murder, whose infected body is found at a biohazard facility; when Arastoo Vaziri is affected by the mutated virus, the only way to save him is to solve the case.

Christopher Pelant returns to toy with the Jeffersonian team; an investigation reveals a string of murders tied to FBI agents; Brennan evaluates her relationship with Booth.

The remains of an accountant for the state department are found in a hotel air conditioning unit; Booth finds an Army buddy and CIA agent, Danny Beck, removing evidence from the victim's condo; Brennan contemplates her future with Booth.

The investigation into the murder of a management consultant whose remains were partially eaten by bobcats leads to a marriage retreat site; Cam's identity is stolen; Sweets decides to take a leave of absence.

The team investigates when a gang member's remains are found in a burnt-out car; when Sweets learns that one of the boys from the center where he volunteers is a gang member's son, he decides to help.

The team devises a plan to use a donated cadaver to draw out Pelant; Sweets returns to work and believes Agent Flynn isn't who he seems.

The team investigates the murder of a high school principal who was dying of cancer; Brennan and Booth plan their wedding; a virtual profiling system threatens Sweets' job.

The team tries to keep the details of an investigation away from Brennan so she will focus on her wedding; Max shows up with a suspicious bag of cash.

Unable to relax on their honeymoon, Booth and Brennan decide to help a local detective solve the murder of a Nazi war criminal; Hodgins and Angela look after Christine.

The team suspects that a man who made his money donating sperm was killed by a recipient who learned his records were inaccurate; Brennan enters a feud with a fellow author (Nora Dunn).

A key witness turns up dead in a case for which Brennan is a juror, so the team works to discover what has happened.

Toby and Michelle investigate a suspicious homicide.

Toby is brought in to investigate some corrupt cops, but finds himself in over his head when one of them ends up dead from a suspected drug overdose.

An imprisoned criminal mastermind holds the key to the whereabouts of a kidnapped judge.

When Michelle and Dev investigate the suspicious death of a CSIS agent, the IIB uncovers a breach of classified intelligence.

Rossi develops some new theories about Everett Lynch, aka The Chameleon; the team sets out on an epic hunt to capture Lynch.

While hallucinating after he gets a brain injury, Dr. Reid is visited by ghosts from his past; the BAU makes a shocking discovery about Lynch that affects Rossi personally; the team comes together to celebrate Rossi's retirement.

The team closes in on a serial killer (Tim Curry) holding Detective Spicer's daughter hostage.

JJ tries to reunite parents with their missing daughter; the team braces for the loss of one of its own.

When several women are murdered, Rossi revisits a 25-year-old case that causes him to suspect a killer is at work again.

The team searches for a serial killer who is preying on married couples; Hotchner looks to a team member to fill JJ's vacant role.

The team pursues a serial killer targeting families in the Midwest; Morgan receives a visit from Ellie after she runs away from her foster family.

The team searches for a killer who has struck the past three years during Detroit's raucous pre-Halloween celebrations.

When bodies turn up in Indiana cornfields, the team must catch a pack of serial killers targeting exotic dancers.

The team tries to stop a killer from striking again after the body of a kidnapped woman is found in an alley.

When an 8-year-old is found dead on the Appalachian Trail, the team searches the forests for a man targeting children.

The team pursues a killer who targets women; Hotchner turns to an FBI cadet for help.

After helping a man get parole, Morgan regrets his decision when the man murders someone shortly after being released.

A series of bizarre, ritualistic murders brings the team to Miami; Reid experiences hallucinations and blinding headaches.

The team pursues two young lovers on a killing spree; Prentiss receives frightening news.

The team investigates unusual murders in Los Angeles, and more information about Prentiss' past arises.

The BAU heads to upstate New York to investigate mysterious disappearances; Prentiss receives troubling news about a former colleague.

Reid's ability to connect with an autistic child may prove helpful in finding the boy's missing parents; two former colleagues help Prentiss search for an old adversary.

After a series of murders, Prentiss becomes suspicious of a former nemesis (Sebastian Roché) and fears for the safety of her team.

Prentiss prepares to confront her nemesis at last; the team asks J.J. to help find Prentiss and capture Doyle.

One of Murdoc's assassins agrees to hand over Murdoc to MacGyver in exchange for $10 million; the team finds itself protecting Murdoc from a former mentor who wants him dead; Jack realizes he may still have feelings for Riley's mother.

The team members pose as honeymoon couples at a resort in an attempt to befriend the son of a Serbian war criminal; Bozer wonders if Matty knows about his relationship with Leanna; Jack recruits Elwood to help him break into Matty's home.

Mac, Jack and Riley set out to find a mobster-turned-informant after he's kidnapped and taken to Chernobyl by an international crime boss; Bozer struggles to keep a secret from Matty.

Mac and the team reunite with the Coltons, a family of bounty hunters, as they all search for a thief of classified intelligence.

As Mac and the team investigate the suspicious death of Dawn's CIA supervisor, the evidence leads to a dirty CIA agent and a massive counterfeiting ring.

Mac and Jack attempt to rescue a billionaire's son after he is kidnapped by a former Navy SEAL.

While helping a friend in Puerto Rico, MacGyver is taken hostage by robbers who are attempting to steal $2 million from the bank his friend manages.

Mac and Riley are called in to examine a mysterious object that crash-landed in the Nevada desert; Riley uncovers new information about Mac's father but questions whether to deliver it to him after he says he needs to move on.

The team identifies the remains of a competitive-eating champion just days before a contest; a brilliant new squint has trouble fitting in; Booth and Brennan try to put themselves in each other's places after a disagreement about the baby.

Booth and Sweets are given access to a toy company's headquarters after an executive's remains are found packaged with a Prince Charming doll; Sweets prepares for his gun certification test; Brennan worries about motherhood.

After dismembered remains are found in multiple mailing boxes, the team uncovers a complicated love triangle; Booth's grandfather reveals surprising news; Special Agent Genny Shaw (Tina Majorino) learns how important teamwork is.

The team suspects murder when a storm chaser is killed while filming a tornado; Booth becomes increasingly protective of Brennan.

After a cryptic message written in human blood is found at a national monument, the team ends up embarking on a scavenger hunt; Brennan and Booth search for their perfect family home.

When the remains of an escaped convict are found in the sewer, the investigation reveals the man died in prison; Brennan gives birth in unconventional circumstances.

When an extreme couponer's remains are found on the side of a road, the investigation leads the team to the supermarket where she shopped; Brennan adjusts to being at work and away from her baby; Cam is unhappy with her daughter's choice of suitors.

A corpse that has been dyed blue is found in a landfill; when Bones feels uncomfortable in her post-baby body, Booth tries to boost her self-confidence.

Booth and Brennan investigate the death of a truck company employee whose body is found in the woods; Hodgins buys new lab equipment; Brennan worries about Parker's return from England.

When a corpse is discovered in the woods, the team considers two families involved in a nearly century-long feud; Brennan is apprehensive when her father (Ryan O'Neal) offers to baby-sit for her daughter.

While in Los Angeles to consult on a film based on her latest book, Brennan discovers the prop cadaver being used is a murder victim; Booth gets a job offer; embarrassing information about Cam's past comes out.

When a past suspect is back in court on appeal, Booth and Brennan work to prove he is guilty once and for all; Brennan becomes a suspect.

After Brennan is accused of murder, her father (Ryan O'Neal) helps her hide from the FBI; Booth and the team think an evil tech genius (Andrew Leeds) manipulated evidence to implicate Brennan.

A powerful divorce lawyer with a lot of enemies is murdered; the three-month separation between Booth and Brennan starts to take its toll.

After an explosion in a hotel garage, the Jeffersonian team tries to identify victims by investigating remains found at the scene; Sweets works with a temporary partner (Danielle Panabaker) while Booth works on the department's budget.

While investigating the death of an animal expo employee, the team is drawn into the world of animal trafficking; Brennan thinks she would be a good presidential candidate; Sweets and Daisy make a change.

Rita Devereaux tells Pride that Douglas Hamilton is about to make a deal to get out of prison; Pride and the team re-investigate the Clearwater case in hopes of spoiling his plans.

After a deadly armed robbery and high-speed chase is linked to an undercover ATF operation, Percy reconnects with her former ATF partner.

Sebastian's high school friend asks for help when her business partner is killed at a gaming convention; FBI Special Agent Raymond Isler believes Adrian is the hacker that the Cyber Crimes division has been tracking for years.

A petty officer's murder leads the team to a nightclub where Pride's mother used to perform; LaSalle must return home to Alabama after receiving an unexpected call from his family.

A petty officer is murdered while in town to help a refugee family; Wade works on the special election campaign for Mayor Zahra Taylor that takes place during Mardi Gras.

FBI Special Agent Raymond Isler asks Pride for help with an off-the-books opioids theft investigation he is personally invested in; Percy works under cover as a getaway driver, with Isler as the muscle for a job tied to the case.

A congressional aide disappears after a hit man saves her from two men posing as NCIS agents; LaSalle struggles with life-altering decisions regarding his brother's future.

The team investigates the murder of a Navy captain who was searching for a priceless 200-year-old fleur-de-lis during the annual Louisiana Pirate Festival.

When the team must locate a girl who purchased a gun from a junkie, it discovers that the firearm, over the course of decades, has affected all of the teammates' lives.

A murdered man's body may hold the key to a 20-year-old case involving a kidnapped girl whose father never stopped looking for her.

Adam investigates the murder of an undercover FBI agent who was about to wed the daughter of a Yakuza leader; Noelani is held hostage and forced, along with her mentor Dr. Chu, to operate at gunpoint on a criminal.

McGarrett helps his sister spy on her shady neighbors; a ride-share driver and his passenger are murdered; the team teases the youngest members when Junior escorts Tani to a wedding.

Fugitive hacker Aaron Wright resurfaces to ask for help when his co-workers at the NSA are murdered; Junior speaks at the parole hearing of the drunken driver who killed his sister.

Five-0 continues to hunt down escaped criminal Aaron Wright before he can sell cyber-weapons to the highest bidder; the lives of McGarrett and the team members are put in danger when a visitor comes to headquarters to make amends.

A new ally helps McGarrett and the team when mob bosses on the island are targeted by an assassin; the team says goodbye to one of its own.

Tani and Junior must plot an escape for themselves and several civilians after they become trapped inside a deadly tunnel collapse; Eddie the dog sniffs out a bomb that has been planted in McGarrett's home.

A plane that mysteriously crashed into the Pacific in the '80s is found, but with a recently murdered scuba diver inside; McGarrett and Quinn zero in on who planted the bomb in his garage; McGarrett formally asks Quinn to join the team.

Five-0 enlists imprisoned hacker Aaron Wright to help when a young girl is reported kidnapped.

The team investigates a home invasion that turned deadly after a dangerous "monster" escaped from the basement; Max returns to Oahu with a very special guest.

A deadly hit-and-run involves a driverless car carrying heroin; Tani and Quinn are stuck with a pair of YouTubers who are brought on a ride-along.

When the CIA informs McGarrett that his mother has gone rogue on her undercover mission and may have killed her partner, Steve goes to Mexico to bring her home and prove her innocence.

The team searches for a killer whose plane crashed in the jungle with $10 million worth of heroin on board; Grover is thrilled when his niece Siobhan comes to try out for the University of Hawaii basketball team.

Junior and Tani track down the thief who robbed his parents' home; Five-0 investigates the murder of a beloved philanthropist and the theft of his valuable koa tree; Danny moves in with McGarrett.

When Adam's girlfriend is kidnapped right in front of him, he shuts out Five-0 and breaks all the rules in order to get her back; the team investigates three seemingly unconnected homicides.

Power is knocked out in Los Angeles, and the team must help a teen pilot and his girlfriend who are lost over the Pacific without any radio contact; Walter must look after a group of Ralph's classmates; Cabe tries to tell Allie that he loves her.

Team Scorpion must prevent an incoming tsunami from hitting a vulnerable nuclear power facility; Toby secretly helps his ex-fiancee retrieve her stolen identity.

On Valentine's Day, Team Scorpion must help a doctor and pilot who are trapped inside a helicopter; Toby and Happy wait for news on their fertility results; Sylvester realizes that he may have feelings for Florence.

The mental faculties of the geniuses of Team Scorpion are impaired while trying to prevent the creation of a black hole; Paige must simplify the science for them; Florence and Sylvester grow closer when she helps him with a special project.

Special Agent Pride and the team investigate a Russian sleeper agent involved with Abby's brother; Sebastian goes to Washington, D.C., to work with Abby; Bishop drives all night to deliver a package and help the New Orleans team.

The staged suicide of a petty officer turns out to be murder; the team secretly works on an online dating profile for Pride.

A Mardi Gras celebration at Pride's bar is cut short when he and Mayor Douglas Hamilton (Steven Weber) are abducted by unknown assailants.

Evidence suggests that the man responsible for saving a lieutenant's life is a soldier who was captured in Afghanistan.

Special Agent Pride and the team uncover a domestic drug ring -- led by Sonja's childhood friend, Marion Watkins (Samaire Armstrong), that is producing cocaine.

A Navy captain is murdered during an appearance on a local radio show; Pride's daughter comes home to talk about her plans for the future.

Agent Brody sees a connection between the case of a sailor struck by a party bus and the death of her sister; the team gets ready for the city's St. Patrick's Day celebrations.

After Pride's daughter is attacked on campus, the team finds a surveillance van loaded with pictures of the special agent's every move.

The team investigates when a Navy lieutenant is murdered during a traditional funeral procession in the French Quarter honoring the recently deceased.

When a Navy lieutenant dies during a secret visit to a general's hotel, agent Pride and the team are asked to break protocol for the investigation.

While visiting her family's restaurant in the French Quarter, a Navy culinary specialist is the target of an explosion; in D.C., Brody tracks a lead in the Gen. Leak case.

NCIS teams with Homeland Security when the murder of a Navy master diver is discovered to be linked to the chatter concerning a foreign attack on the city.

The NCIS team discovers a mole in the ranks while helping the Department of Homeland Security locate 900 pounds of missing explosives that are a threat to New Orleans.

The team joins forces with several federal agencies to stop a sniper who has been targeting crowded events in the city; FBI Special Agent Tammy Gregorio begins investigating Pride's team.

Pride faces more repercussions from the FBI after he helps a former Navy Intelligence Analyst who is the primary suspect in a multiple homicide case.

After the discovery of a petty officer's body inside a sports arena, evidence leads Pride and the NCIS team to a kidnapping case of another petty officer, last seen in Mexico.

The NCIS must come to the rescue of one of its own when Sebastian is kidnapped while dining in a restaurant with his mother; Sebastian relies on his gaming skills in a prison break.

The NCIS and the FBI investigate a private plane crash in the bayou that killed three sailors; Sonja and Lasalle interview candidates for a job opening on the team.

A Navy SEAL candidate is murdered weeks before his graduation; Wade seeks Pride's help when her adopted son announces his plan to join the Navy.

A sailor is murdered during a rowdy motorcycle rally in the city; Lasalle seeks personal advice from Gregorio.

The team is taken hostage when it inadvertently crashes a bank robbery in progress; Sylvester's feelings for Florence grow.

Team Scorpion heads to the bayou to track down a cagey alligator to stop a deadly virus; Paige teaches Walter the concept of the "white lie"; Walter hits Cabe with a tranquilizer gun, and Toby must save his life.

Team Scorpion must use their high IQs to win a softball game; Walter's secret night out with Florence puts Toby and Happy on edge.

Paige's maternal side goes into high gear when an unconscious boy gets stuck in the wheel well of an airborne airplane; Walter's white lie to Paige starts to take a toll on him; Paige realizes something is amiss.

The investigators probe what appears to be gang-related gunplay in a hospital emergency room, then discover a cheating girlfriend may be the catalyst for the shooting.

Horatio and the team look for a killer wanted for the murder of a police officer during a traffic stop, but their only lead is an eyewitness report from a suspicious teenage girl.

The murder of a bellboy during tourist season leaves detectives with many suspects, but the luggage he had been loading helps them to uncover a complex counterfeiting operation.

When a woman is swallowed whole by a giant snake, the CSI team suspects that Horatio's nemesis, Clavo Cruz, is behind an operation that uses snakes to smuggle drugs into the country.

The team must find the person who caused a jet carrying $1.2 billion in checks to crash in a suburban neighborhood.

The Five-0 helps a private investigator in the case of a kidnapped woman whose husband may have something to hide; Rachel tells Danny that she is getting a divorce from Stan.

McGarrett and the Five-0 are captured while tracking a dangerous nemesis to the island of Lanai; Grover takes his son to Chicago, where he testifies against a dirty cop.

McGarrett works the murder case of one of the last survivors of the USS Arizona; Adam uncovers bone fragments at his new construction job.

Danny protects a coma patient who was the key witness from his last case at the Hawaiian Police Department.

McGarrett gets a tip that someone is plotting a terror attack on Oahu; Chin and Abby face a difficult decision.

McGarrett risks his life when Five-0 attempts to rescue the young girls trapped in the sex trafficking ring they have been tracking; Kono makes a life-changing decision.

McGarrett and Danny recruit Tani Rey to join the task force when a hacker releases a dangerous arsonist from prison.

McGarrett and the team work with an injured police dog that is the only witness to an ambushed drug bust; a former SEAL looks to join the task force.

The team enlists an old friend when a crime boss is murdered, triggering revenge killings across the island; MacGarrett and Danny work out details concerning their new restaurant venture.

When the HPD system is hacked and one of the Five-0's informants ends up dead, McGarrett enlists the help of hacker Aaron Wright, whom he just imprisoned.

At Halloween, the team investigates a string of murders that mirrors stories from well-known Hawaiian folklore; Grover visits a man who is hours away from execution and may hold the key to a case that has plagued Grover for years.

The murder of two tourists leads the team to a man who has multiple personality disorder; Danny and the others hire a stress management consultant to help McGarrett.

A bank heist in progress forces Steve to make a potentially heartbreaking mistake; Adam faces an empty home without Kono.

McGarrett poses as a pilot to investigate a plane crash that led to the death of a pilot in an air race.

McGarrett, Danny, Tani, and Junior are exposed to a deadly biological weapon; the rest of the team has eight hours to find an antidote.

MacGyver gets a shocking surprise when he tries to tell Matty he's quitting the Phoenix Foundation.

Three months after quitting the Phoenix Foundation and moving to Nigeria, Mac puts aside his differences with his father and returns when he hears Jack is the target of a murderous dictator he double-crossed.

Jack receives an emergency distress signal from one of his old Delta buddies who has been accused of terrorism in a foreign country; MacGyver and Jack quickly recruit the rest of Jack's old Delta team and stage an unsanctioned rescue operation.

MacGyver and the team go under cover on a college campus to find an operative who is recruiting students to carry out deadly attacks; Jack joins bounty hunter Billy Colton in the hunt for a bail jumper.

MacGyver and Riley must find a way to drive a tanker filled with liquid oxygen through a region occupied by rebels and deliver it to a children's hospital; Riley helps MacGyver decide whether or not to allow his father back into his life.

Mac and Jack rush to Mexico to help capture the leader of a drug cartel while the country celebrates Dia de Muertos.

Murdoc abducts MacGyver's girlfriend to force Mac to help him rescue his son from a kidnapper; a dangerous person from Murdoc's personal life shows up, giving Mac a glimpse into the villain's past.

Matty sends the team to Ghana to recover a hard drive from an e-waste landfill that is run by a powerful and violent man, leading them to speculate about what could be on the device.

A murder in a Florida community of sex offenders results in a large number of possible suspects; a career opportunity could take Lewis away from the BAU.

Rossi's daughter, a journalist, investigates the disappearance of a college student; JJ comes back from maternity leave.

An unknown subject in Phoenix abducts people and deprives them of sleep; Garcia and Hotch deal with a threat from hit men.

The BAU works with the NSA when two undercover DEA agents are murdered and another goes missing; Hotch hopes the team's work with the NSA will bring them closer to finding a ring of hit men.

The members of the BAU team track an unknown subject who appears to be fascinated with medical experimentation.

Reid plays a central role in the BAU's elaborate plan to take down a ring of hit men known as the Dirty Dozen.

When corpses are discovered in public places in Boston, a ride-sharing service may lead the team to the killer.

The BAU looks for a suspect and a motive when victims are found in truck stop restrooms in the South.

An 18-year-old woman escapes from the home where she and two other women were held captive for years.

The BAU team combs Los Angeles for a suspect after security footage is discovered, which shows an unknown subject being invited into victims' homes.

When Morgan is abducted, the members of the BAU team race against time to find him and save his life.

The team searches for an unknown subject who takes children while their parents are asleep; Morgan tries to find out who attacked him.

When an unsub targets the BAU, the team pursues the person who is responsible for the actions.

Emily looks to the BAU for help when tracking an international serial killer; the BAU deals with Morgan's departure.

The BAU hunts for an UnSUB who deliberately disfigures victims; Rossi and his ex-wife have an uncomfortable reunion.

The BAU plays a dangerous cat and mouse game with a convicted serial killer who may have information on the whereabouts of two kidnapped boys.

Horatio and the team race against time to find a killer who escaped from prison while helping to fight a fire in the Everglades; a local college student is found shot, but the blaze has destroyed the crime scene and evidence.

The team investigates the possible murder of Jake Sullivan (Tony Hawk), a skateboarder and video-game tester.

When an IRS agent is killed trying to repossess a yacht, and another is shot to death soon afterward, the team searches for the perpetrators in a potential series of murders before tax day.

Horatio gets life changing information about his deceased brother.

When a bitter custody battle ends with a courthouse murder, the team must use the available evidence to find the killer.

When there is a murder at a high-school reunion, the team investigates and learns that popularity issues from the past played a role in the killer's motives.

When a condemned ax-murderer on death row appeals for his life, the team must investigate.

Horatio finally learns the truth about what happened to his brother, and the repercussions will change his life forever.

Horatio finds himself with a price on his head when he makes plans to shut down the illegal smuggling operation of one of Miami's fiercest gangs.

A rich couple's daughter dies when the family is trapped on a burning yacht in shark-infested waters.

When a teenage tourist goes missing, the team investigates the dark side of Miami's nightclub scene.

The team investigates the murder of a food scientist whose body was put through a meat grinder and mixed into canned stew; Angela puts together a post-wedding bachelorette party for Brennan.

When a gymnast's remains are found in a park, Booth and Brennan discover she was living a double life; Cam confronts the woman who stole her identity.

The team investigates when the remains of a girl who died 18 years earlier are delivered to Brennan and Booth's house; Brennan dreams about Pelant.

The team investigates the death of a country music singer whose remains were found in a shallow grave; Brennan takes a look at Wendall's injuries after he breaks his arm during a hockey game.

Sweets goes undercover in the chess world to find a killer; Cam gets a science award but fears offending Brennan, who feels she deserves it; a sunny new podiatrist intern annoys Brennan.

The team investigates the murder of a kidnap victim whose remains were found at a park; Hodgins makes a discovery about his family; Brennan and Boothe consider co-mingling their money.

Booth and CIA agent Danny Beck (Freddie Prinze Jr.) must track down a terrorist after a CIA informant is murdered; Brennan and Booth must consider the ramifications when Brennan wants to do more work in the field with Booth.

When the remains of a repo man are found in a septic tank, the team learns he had a troubled past; a forensic anthropologist (Ignacio Serricchio) who has defected from Cuba needs an internship.

When an actor known for playing a popular character on a kids' TV show is murdered, unexpected suspects are discovered; Brennan and Booth plan a party for Christine's birthday; Clark asks for opinions on his novel.

When a wealthy artifact collector walks into his own funeral, the team must determine the real identity of the deceased; Finn's new hot sauce venture is making big money.

The remains of a former art student are found in a log in a forest; Wendell returns after beginning cancer treatments; Booth prepares for an FBI competency test.

The team investigates the death of a woman whose body was cryogenically frozen before being dumped in a swamp; Cam is nervous to meet Arastoo's parents; Booth is up for a promotion.

A routine trip to the hospital leads a wealthy businessman to lose his baby daughter after his SUV is hijacked.

A break in a six-month cyber crime investigation leads Michelle and Dev to pursue a reckless hacker.

Toby and Oz are taken hostage by two men posing as security guards when they are dispatched to a routine call in the financial district.

A celebrated restaurant chef is a star witness in the trial of a mob boss charged with shooting his business partner.

The team must stop a gang of suspected murderers that is targeting a new victim nightly.

The team must investigate targeted killings in Florida while each member is dealing with feelings about losing Prentiss.

A stalker in San Diego targets college students; Strauss scrutinizes the team after the loss of Prentiss.

The team travels to a North Carolina town where one woman was found badly injured and another is missing, and discovers those may not be the only victims.

The team investigates when bodies are found buried beneath the ocean floor off Florida; Morgan is rattled when his aunt thinks her missing daughter is one of the victims.

The team investigates a suspected human trafficking ring; Hotchner suggests changes are coming; J.J. returns to the team.

A Senate committee questions the members of the BAU team; a familiar face may help keep the team united.

The BAU team investigates a series of murders in Oklahoma; Reid gives JJ and Prentiss the cold shoulder.

After a mass murder at an Internet security company, evidence indicates that the person responsible is not a typical serial killer; Prentiss is required to complete recertification training.

A killer targets survivors of a high-school massacre, who have gathered for a reunion; Hotch fears that his son is being bullied.

A series of children are abducted from troubled women in St. Louis; Rossi's first wife shares shocking news.

The team investigates when multiple bodies are found in a national forest; Rossi faces an agonizing decision.

The BAU investigates when bodies are exposed by tornadoes in Kansas; pressure at work affects J.J. at home.