When the serial killer that Alicia and McGarrett have been hunting kidnaps them, it's up to Five-0 to find them before it's too late.

A cache of guns is stolen by a person looking to make a statement on gun violence; Kono and Adam are reunited.

On Halloween, the team investigates the murder of a medium who was apparently frightened to death by a poltergeist; a mysterious death cult kidnaps Kono and Adam.

Team Scorpion continues work with their nemesis to prevent humanity's extinction; Cabe's last-minute decision while on the case endangers his career.

When poachers almost kill a pregnant deer, the team tries to save the deer and the fawn; Happy and Toby discuss the future of their family.

While decommissioning an old nuclear missile, an accident causes the team to endure exposure to toxic vapor while trying to prevent the nuke from detonating; Paige confronts Happy about constantly tagging along with her and Walter.

While attending a tech convention, Team Scorpion is taken hostage by a group attempting a virtual heist.

Pride starts to doubt evidence suggesting homeless kids murdered a petty officer.

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 undercover 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.

Pride, Sebastian and Tammy travel to South America after Pride is personally requested by a former colleague to assist with a classified operation that has been compromised.

Percy and LaSalle go undercover at a high-stakes poker game after the organizer targets players with access to a naval research laboratory; Laurel Pride visits her dad during spring break to discuss options after her upcoming graduation.

Pride and his bar patrons are held hostage by a group of volatile thieves.

Gregorio calls on her former behavioral science professor when the team's latest case matches one she studied during FBI training.

A journalist posts a scathing article documenting Pride's "reckless use of justice"; the team is concerned about the fallout from the piece and the confidential information revealed; Rita Devereaux tells Pride it is a coordinated attack on him.

Pride assembles an off-the-books team to search for a loophole when he faces a grand jury indictment for abuse of power.

Pride's teams uncover a sinister plot during the New Orleans Tricentennial Fleet Week celebration.

While Pride fights for his life in the ICU, the team scours the city for the hit woman who attempted to assassinate him.

The team searches for a former Irish Republican Army bomb maker who was smuggled into the city; they are joined by agent Hannah Khoury, Pride's replacement during his medical leave; Pride considers a new position within the agency.

The team investigates the murder of a Navy intelligence officer killed during a conference for foreign diplomats; Pride has some trouble adjusting to his new position at the agency.

An investigation into the murder of a petty officer reveals a conspiracy in a tight-knit local fishing community; LaSalle awaits the final results of the tax fraud investigation into his family's company.

At Halloween, the team takes on a case to prove the existence of ghosts on the Queen Mary but find a ship on a deadly collision course; Walter considers taking note of Paige's interests to benefit their relationship.

A device that can prevent a nuclear meltdown is tracked through the Los Angeles sewers; Walter learns to listen and not offer advice to Paige; the team meets their new neighbor.

Team Scorpion visits a renaissance festival, but the revelry is cut short when a group tries to rob a nearby police evidence locker; Paige grows weary of Walter pointing out the historical inaccuracies at the festival.

Team Scorpion becomes stranded on a floating island of trash they were trying to destroy; Toby works with Cabe to uncover the details of his father's death.

Horatio uncovers a scandal that pits him against a former adversary; Calleigh faces a life-altering decision.

When an enemy of the CSIs is killed, Horatio looks to his team for a suspect.

The team searches for evidence and survivors after a jet crashes into the Everglades, trying to recreate what transpired on the fatal flight.

Horatio sets out on a personal mission to find his mentor's killer, and Megan worries that he has become too emotionally involved in the case.

Horatio and Megan examine the remains of a human torso found in a tiger shark's stomach. Wanda De Jesus guest stars.

When a missing artifact seems to be the key to solving a double murder, a conspiracy theorist (Jorge Garcia) helps the team.

When a wedding crasher is murdered, a runaway bride is the prime suspect; Danny makes a decision about his relationship with Gabby.

A seemingly harmless surveillance job turns deadly; in hope of saving Kono, Adam considers making a sacrifice.

When a zombielike man is shot, the team members are led to a madman who is performing experiments on humans.

When Mary gets sick, McGarrett and the team must watch her newly adopted baby while they investigate the murder of an undercover ATF agent.

The governor asks McGarrett and Grover to serve a warrant to a young computer hacker (Nick Jonas) in order to protect national security.

A Secret Service agent is murdered while the president is traveling to Oahu; as Thanksgiving approaches, McGarrett's Aunt Deb (Carol Burnett) visits and shares a stunning secret.

An attempted murder leads the team to investigate a deadly crime committed in Hawaii during World War II.

An investigation involving a potential serial killer puts Chin's life in danger; Grace and Danny find a mysterious puzzle box.

One of Grover's friends disappears after apparently committing a murder.

Chin is questioned about his father's murder and how his relationship with Malia and her family could have adversely affected the investigation.

An escaped convict who wants Five-0 to prove his innocence abducts Danny and McGarrett; Grace punches a person at school.

The team investigates the death of a real estate agent whose body was found in the walls of one of his listings; Danny's mother visits with unexpected news.

A triple homicide is linked to a secret, downed Chinese satellite; Danny's mother goes on a ride-along with Grover.

A man is shot as his daughter is abducted; Danny tries to reunite his parents; Jerry finds a code on McGarrett's champ box.

While Mac and Jack are tracking a dangerous fugitive, a family of bounty hunters kidnap him; Bozer and Riley try to hack into Jack's CIA file.

When Mac and the team are blamed for a terrorist bombing, the Phoenix Foundation is forced to disavow them; the team must clear their names without support from back home.

After an earthquake in Hawaii, Mac and the team join Chin and Kono from the Five-0 task force to rescue a group of government scientists trapped in a building; another group tries to steal top-secret weaponry from the scientists.

Mac's close friend from M.I.T. fakes her own death to prevent someone from killing her to suppress her scientific research.

When the team intercepts a terror group's message for Murdoc, instructing him to kill a tech analyst, Mac poses as a psychopath to save the intended victim.

Murdoc moves ahead with his plans for revenge against MacGyver by recruiting his recently released former cellmate to infiltrate the Phoenix Complex and kill every agent inside.

MacGyver uses a cell phone and soccer ball in the search for a Navy SEAL who is believed to be held captive in the Middle East.

Riley disappears during her first solo mission; Mac and the team attempt to locate her.

The BAU team must determine if the anniversary of the Kennedy assassination is a motivating factor when a sniper strikes Dallas.

The BAU team meets the new section chief (Esai Morales), who shares a long history with J.J.; an unknown subject leaves victims unable to communicate.

As Hotch fights for his life after being stabbed, he has visions of his late wife and his nemesis; when a teen goes missing, suspicions arise about her estranged father.

Ritualistic murders lead the team to believe their suspect may have a fascination with the Salem witch trials; Garcia plans a Day of the Dead celebration.

A series of strangulations leads the team to look for a killer who keeps mementos of his victims; Rossi's favorite bar is in danger of closing.

The team searches for missing teens who are suspects in a series of mass murders in Chicago.

When skeletons are discovered in the backyard of a home in Virginia, family secrets and past racial divisions are brought to light.

When a young boy disappears from his home in St. Louis, the team examines a similar cold case for clues.

Blake must work with her retired police captain father and her detective brother to solve a series of murders in Kansas City.

A murder investigation results in Garcia delving into her hacker past -- and reconnecting with a former flame.

As the team searches for a vigilante killer in Cleveland, Rossi's former Marine sergeant goes missing in Los Angeles; J.J.'s secret catches up with her.

The BAU learns of JJ's kidnapping, they discover that Cruz has also been abducted and delve into the files of a classified assignment; the team uncovers details of INTEGRITY, the covert database born out of the operation to find Osama bin Laden.

The team searches for a pair of suspects responsible for several murders near Pittsburgh; Morgan and Garcia make Valentine's Day plans with their significant others.

The BAU makes startling discoveries as they search for a 4-year-old girl who went missing while staying with a relative.

The BAU must determine the true cause and motive when several drowned people are discovered in the Las Vegas desert.

Three bodies bitten by humans and animals are found in a shallow grave; Garcia and Reid hide their preparation for a company fitness test from Morgan.

A wealthy family uses their power and influence to distance themselves from a rape and murder investigation.

A priest is shot to death in his church rectory; Horatio and Delko examine the charred remains of a pregnant woman.

Horatio and the team investigate the murder of a 5-year-old girl in a restaurant washroom.

Poisoning is suspected as the team probes the murder of a male stripper found dead in the wake of a female sex party; a deep sea diver is fatally stabbed while underwater.

Evidence on a lost, blood-soaked toddler leads the CSI team to her home where each family member's spilled blood tells a tale of horror. Wanda De Jesus guest stars.

The team tries to get inside the mind of a sniper after three people are shot and killed in downtown Miami.

Horatio and the team investigate after the corpse of an unidentified girl is found near an extremely strict rehabilitation camp.

Horatio investigates the stabbing death of a prostitute who is found stuffed under a bed in a hotel room.

Horatio and Speedle investigate the manufacture of lethal drugs at mobile labs; an elderly woman is murdered at a senior citizen home.

A serial rapist is found dead of suffocation; investigators probe the murders of a crematorium owner and a girl found behind the crematorium.

Team members meet an environmental lawyer who has radiation poisoning after they are exposed to radiation during an investigation.

A man stands trial for a murder he didn't commit, while Horatio and the team race to find the real killer.

The remains of a hoarder are discovered; Angela's father (Billy Gibbons) visits; Booth and Brennan are each confronted with unique opportunities.

The team helps Cam solve the case of an unidentified boy; after making personal discoveries, the members of the team realize they belong in Washington, D.C.

The remains of a couple are found in a cave; Brennan re-evaluates her relationship with Booth when his girlfriend makes a surprise visit.

Brennan and Booth head to the Jersey Shore when decomposed remains are discovered; the team becomes fond of Booth's girlfriend; Angela tries to keep a secret.

When a skull and decomposing hands are found in a dumpster, the team searches for the rest of the victim's remains; Brennan agrees to shoot an episode of a children's show with professor Bunsen, "The Science Dude" Jude (David Alan Grier).

The skull of a promising young dancer is discovered at a construction site; Hannah's safety is jeopardized when an assignment takes her to a dangerous part of town.

Human remains from a 150-year-old slave ship surface; the investigation leads Booth and Brennan to a cruise where a murder victim is seen moments before his death.

An event for a candy maker (Wayne Knight) turns bitter when human remains are discovered in the world's largest chocolate bar; Cam struggles with her daughter's decision to attend a college that fails to meet her high standards.

Brennan and Booth investigate a crime scene where a human carcass has melted to the dashboard of a charred truck; Sweets tries to keep his feelings for Daisy from interfering while helping her pass a government psychological evaluation.

A brilliant and career-driven surgeon is found dead in a rough neighborhood; a new friend helps Brennan make a discovery about herself.

A body is found in the shower of a home belonging to a young socialite; Hodgins and Angela talk about their future; Booth talks to Hannah about Brennan's feeling for him.

The Jeffersonian team investigates when a notorious murderer known as "The Gravedigger" (Deirdre Lovejoy) is killed by a sniper.

The team investigates the murder of a cooking show contestant, poisoned on live television.

While investigating the murder of a billionaire playboy, Toby's curiosities about his family arise.

After being drugged, Toby is implicated in an armed kidnapping.

Toby goes under cover when he believes an innocent man is taking the fall for a murder.

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.

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.

MacGyver and the team must steal diamonds before terrorists beat them to it and trade the jewels for a weapon of mass destruction.

When Murdoc drugs and kidnaps MacGyver, Mac must escape and join the team to save Murdoc's next victim.

The team's Halloween plans are interrupted when the vice president's son's plane goes down with a mysterious prisoner on board.

Mac and the team attempt to extinguish a massive oil wellhead fire set by a rebel group in Nigeria.

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.

When the corpse of the host of a popular reality show is found partially decomposed in an outhouse, Brennan and Booth must separate the killer from many suspects; Booth discovers that Brennan juggles two relationships.

When Booth's son, Parker, finds a finger in a bird's nest, the team launches an investigation to find the rest of the body; Booth asks Sweets to psychoanalyze his son; Sweets confronts Hodgins about his attitude in the lab.

A teen discovers a dismembered, headless body in a pool of purple water; the team struggles to find enough evidence to locate a killer until getting insight from Zack, who studies the case at his psychiatric facility.

Booth and Brennan investigate when the remains of a disliked office manager are found in a building elevator shaft; Angela and Hodgins try to figure out their altered relationship.

Skeletal remains with remnants of breast implants are found in the Chesapeake Bay; when the body's lower half is discovered, the team realizes that initial assumptions about the victim may be wrong.

When the smashed remains of a famous artist are found in an impounded junkyard car, the team must race against the clock to find evidence of murder before the car is put on exhibit as the sculptor's ultimate display for the sake of his art.

A con man misleads the team during a murder investigation; Booth's younger brother, Jared, takes a job at the Pentagon; Brennan agrees to go on a date with Jared to a White House function.

While en route to China to identify prehistoric anthropological remains, Booth and Brennan are called upon to solve a murder in midair when the flight attendant discovers a fully cooked human body in the plane's microwave.

Brennan and Booth investigate when a skull and other skeletal remains are found in a nationally protected wooded preserve; Brennan's recently acquitted father (Ryan O'Neal) finds a job as a teacher.

A shallow grave holds the remains of conjoined twins; Booth and Brennan infiltrate a circus community after they discover that the twins were jugglers there.

A man and his son discover a frozen body in a pond; Booth gets advice from one of his hockey idols.

Brennan and the team get a phone call from the Grave Digger, who informs them that Booth has been buried alive with only 24 hours of oxygen.

The team investigates at a fantasy convention when a female science-fiction enthusiast is found murdered.

While bungee-jumping, a couple discover a corpse at the bottom of a gorge; the lab goes into lockdown when an unknown substance begins oozing from the cadaver.

The body of a pregnant 16-year-old athlete found buried in a mound of salt in a city de-icing truck leads Booth and Brennan to the discovery that many of her teammates are pregnant or have babies after a pregnancy pact.

Booth and Brennan are convinced the death was no accident after the half-eaten body of Cam's ex is found in the tiger cage at the zoo, leading the team to hypnotize one suspect (Chad Lowe) to try to jog his memory.

Pride and the team must go on a dangerous undercover mission to retrieve a stolen missile and prevent an attack.

A blogger dedicated to exposing government corruption is murdered; during the investigation, it is revealed that a war crime may have occurred during a humanitarian effort in Bolivia.

When a highly regarded Navy pilot is killed after crashing a new, high-tech jet at an air show, the team must determine if it was human or mechanical error.

The NCIS team investigates when a Navy drone pilot is murdered after using a black market drone to obtain military surveillance.

When an Australian Royal Navy Lieutenant is murdered in New Orleans, Special Agent Naomi Parsons (Kate Beahan) is sent to work with Special Agent Pride.

When a petty officer is found dead, the team's participation in the annual Red Dress Run comes to a halt.

An extremely intelligent Navy coder -- employed by Brody's mom (Annie Potts) -- is put in danger when the heart intended for him is stolen.

After traveling to Texas to escort a key witness to the trial of an infamous arms dealer, Sonja and Special Agent Pride are ambushed.

Catherine informs Five-0 that McGarrett's mother has been captured and is in danger of being executed for trying to free Wo Fat's imprisoned father; Chin is unable to delay Sara's adoption.

While Danny chaperones Grace's high school dance, the venue is seized by terrorists, who hold everyone hostage with the intent of abducting a diplomat's son; Danny and Grover discover that Will is Grace's secret boyfriend.

A conspiracy theorist with compelling information that JFK's own cabinet planned his assassination is murdered.

A boy suffering from PTSD undergoes hypnosis and realizes he may have witnessed a murder related to a 10-year-old cold case; Danny's sister visits Oahu.

The team rushes to Mexico, where Chin puts his life in jeopardy in an effort to rescue Sara, his kidnapped niece.

When Chin is kidnapped by a Mexican cartel, Five-0 must rescue him before he is executed by the vengeful group; Grover goes undercover to investigate a murder, which turns out to be far more complex and dangerous than anticipated.

While Max prepares to say his goodbyes, the team investigates a murder during a police convention on the island.

The team faces a contentious U.S. Marshall after a murder suspect escapes capture and looks for asylum in the sovereign land that belongs to the Nation of Hawaii.

While working a murder case, Five-0 discovers that a former Nazi war criminal may be hiding out in an old leprosy colony in Hawaii.

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.

The Five-0 must once again engage in the twisted mind games of serial killer Dr. Madison Gray when she arrives at the HPD covered in blood that matches Alicia Brown's.

After tracking down the missing uranium, which has been used to build a bomb in the middle of the jungle, McGarrett and Danny must move the explosive material through treacherous terrain before it detonates.

McGarrett and Kono suspect that an abused young girl may be the victim of a sex trafficking ring on the Island; Chin and Grover investigate a murder at a sober living facility.

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.

Team Scorpion tries to help a father and his daughter when their plane crashes nearby; Paige helps Walter navigate his feelings about Cabe's possible future in prison.

The team anxiously awaits the verdict of Cabe's trial which could send him to prison; they use their nervous energy to try saving a dog stuck in a cistern.

On Christmas Eve, Walter becomes unconscious after falling down the stairs and enters a dream world where Team Scorpion never existed.

The team must work with Toby's nemesis and his wife -- Toby's ex-fiancée -- when they are locked inside an artificially intelligent doomsday bunker that aims to kill them; Walter is distracted by a dream in which he married Florence instead of Paige.

Pride's father, Cassius Pride, is wrapped up in an NCIS case involving a notorious unsolved casino heist; Pride meets a family member he never knew existed.

After Pride's assistant escapes from a kidnapper, the team uncovers evidence of a suspect who is harvesting organs from multiple victims; Pride turns to a friend for guidance as he struggles with the ramifications of his recent brush with death.

Following a deadly car explosion in the French Quarter, the team interrogates a professor and former member of a student protest organization; Tammy discovers a secret about Hannah's personal life.

The team places Mateo Diaz, a high school gang member turned informant, in protective custody while they investigate the murder of his junior reserve officers' training corps instructor; Pride needs his brother's help to gain Mateo's trust.

The team investigates the murder of a Navy contractor who secretly lived two lives for decades.

Pride is given a series of tasks to complete by unknown assailants who are holding Wade and his father hostage.

Pride and the team hope to take down a secret and lethal group of former intelligence agents and avenge the death of someone close to them.

While undercover, Gregorio joins a social club for military wives after one of the members is contacted by an ex-boyfriend who is on the FBI's most wanted list.

NCIS investigates the disappearance of a Navy entomologist after a deadly shooting at a research lab; the team finds that a rare and deadly virus was stolen.

Pride and the team reunite with conspiracy journalist Oliver Crane after the source for his latest story is murdered; Hannah's former partner, Liam Somers, surprises her and shares a shocking revelation about an old case.

The team investigates multiple murders tied to a construction company that creates an experimental chemical that strengthens sea walls; evidence from Hannah's previous mission in Oman is used against her.

After an elusive terrorist with a personal vendetta against Hannah resurfaces, she and her family are placed in protective custody while the team searches for the suspect.

After a reshuffling of assignments, Pride returns to the New Orleans office during the investigation of a missing petty officer.

The NCIS team investigates the murder of Patton's friend, a former Navy SEAL gunned down in a drive-by shooting while Patton watched.

A Navy lieutenant from a well-connected and affluent family has a fatal fall down a flight of stairs at a charity gala; the team investigates whether his death was an accident or foul play.

When Elvis Bertrand's "daughter" is linked to a murder case, he asks Pride to prove her innocence.

Tammy is convinced that a con man committed the hit-and-run murder of a Navy doctor, even though the evidence shows otherwise; unbeknownst to Hannah, her husband approaches Pride with new intel on an underground spy network.

The NCIS team investigates a deadly bombing at a military museum event with over 1,000 people in attendance.

Pride and LaSalle travel to war-torn South Ossetia to locate an FBI agent who was kidnapped during a failed mission to apprehend the leader of Apollyon, the underground spy network responsible for murdering Pride's father.

After tracking Apollyon, a deadly underground spy network, to war-torn South Ossetia, Pride is separated from the team and faces grave danger; in order to save Pride, the NCIS team must locate a mole who continues to feed information to Apollyon.

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.

Routine disposal of drug evidence goes horribly wrong, leaving two police officers dead and the CSI team under investigation.

Horatio wants to question a murder victim's boyfriend, but the FBI won't divulge his location; Calleigh's father pays a visit.

An ex-con asks Horatio to help him find his missing son; Speedle investigates a man's death by asphyxia.

Marks on a female corpse on a beach lead Horatio to think the perpetrator is a serial killer who bites victims; Calleigh and Delko investigate a murder at a motel pool.

The team investigates when a fire engulfs a popular nightclub, killing 16 people and injuring 58 others.

The daughter of a macadamia nut tycoon is killed with a stiletto heel during Chin's high school reunion.

Danny and McGarrett are trapped inside an abandoned building rigged to explode.

A murder investigation leads the team to uncover a possible terrorist cell planning an attack on U.S. soil.

Catherine and McGarrett go to Afghanistan to help a young boy, whose family saved Catherine years earlier.

Grover is forced to steal $100 million when a nemesis kidnaps his daughter; Wo Fat goes back to Oahu after escaping from prison.

O'ahu goes on lockdown as the team looks for a terrorist who is using weaponized drones on civilians; McGarrett and Danno attend a review with a psychologist.

While a Navy SEAL is on a secret mission, his young daughter is kidnapped; Danny must find $18.5 million in order to save his brother.

Three female thieves unwittingly make themselves serious targets when they take something during a tour bus robbery; Danny searches for his brother's money.

When a man from Detroit is killed on the streets of Oahu, the team is shocked to discover the killer's motives; Chin risks everything to help Danny.

McGarrett meets a woman who helps him reopen the last cold case his father investigated before dying.

On Halloween, the team hunts a serial killer who mimics murders from a cult slasher film; Jerry is abducted by counterfeiters.

McGarrett experiences what would have happened to the team had they taken a different path when he is kidnapped by Wo Fat.

Sons become the prime suspects in the murder of their parents; Aunt Deb shocks McGarrett when she returns to the island with her new fiancé.

When a cowboy is poisoned, Max must work with a rival medical examiner; McGarrett wants Danny to steal a Christmas tree.

An old-school private detective helps the Five-0 solve the murder of a young woman who secretly worked as an escort.

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.

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.

Morgan's visit with a survivor of unusual stabbings in upstate New York leads to more questions about the case.

The discovery of two murder victims in West Virginia uncovers a long-simmering feud between two families.

The team searches for a commonality when a series of target abductions take place; Savannah is frustrated with Morgan's traveling.

When people are killed by arsenic poisoning and handwritten death threats are found, the team pursues a suspect fascinated by Greek mythology; Hotch is worried about participating in a Career Day at Jack's school.

When prostitutes are murdered in Texas, their deaths seem to have religious overtones; members of the team are put at risk throughout the course of the investigation.

The investigation in Texas reveals a deep web of corruption; Garcia must save a friend.

The team investigates a series of murders with unidentifiable victims in Bakersfield, Calif.; agent Kate Callahan joins the team.

The team members search for a vengeful suspect who was once abused; Garcia travels to Texas to confront the person she shot.

The BAU team goes to Colorado to investigate when a passenger jet crashes; the incident reminds Kate of a family tragedy.

A body is found covered in scratches, leading the BAU to believe that the person responsible has a chronic skin disorder.