McGarrett and Five-0 once again become entangled in the twisted mind games of serial killer Dr. Madison Gray when she stumbles into HPD covered in blood that matches Alicia Brown's and claims she has amnesia.moreless
Five-0 investigates a murder involving the illegal practice of shark finning and, during the probe, uncovers the possibility that a former Nazi war criminal may be hiding out in an old leper colony in Hawaii.moreless
Five-0 must negotiate between the law and local customs when a man wanted for murder escapes capture and seeks asylum in sovereign land belonging to the Nation of Hawaii.
Danny chaperones Grace's winter formal but terrorists seize the venue and hold everyone hostage in order to kidnap a diplomat's son. Also, Danny and Grover are shocked to learn that Will is Grace's secret boyfriend.moreless
McGarrett and Alicia are kidnapped by the serial killer who has been terrorizing the island after they discover his identity.
FBI profiler Alicia Brown is forced to join McGarrett in the hunt for the chess-piece killer when she finds a body in her bed. Meanwhile, Kono reconnects with a former surfing competitor who is now a disabled and homeless war veteran.moreless
Five-0 works with rogue MI-6 agent Harry Langford to find a terrorist planning to cause nuclear reactors across Europe to melt down. Meanwhile, McGarrett and Danny ask retired FBI profiler Alicia Brown to help them find a serial killer vigilante.moreless
Season 7 begins with the body of a serial killer being found in Five-0 headquarters with an ivory chess piece in his mouth. When a second serial killer is found dead with another chess piece, Five-0 hunts for the vigilante as fear spreads that it's not safe to travel to Hawaii. Meanwhile, McGarrett refuses to take it easy, even though he is recovering from surgery.moreless
Five-0 gets trapped inside a dilapidated building in Oahu's Chinatown, where they try to protect a wounded Gabriel and plan their escape. But gunmen looking to kill Gabriel storm the building.
A woman is murdered in her home and Five-0 learns that one of their own has a deep connection to the victim's young daughter.
Five-0 tries to save a kidnapped college student from a dangerous vigilante. Meanwhile, Max, Kamekona and Flippa fight to survive after being shipwrecked.
Five-0 goes on a manhunt when a chemical spill permits six dangerous inmates to escape, including Kono's husband, Adam.
Five-0 investigates the theft of a high-tech, indestructible suit created for the U.S. military. Meanwhile, Jerry tries to help his sister save a captive elephant.
Five-0 hunts a Russian spy who stole a flash drive containing classified NSA information that puts one of their own at risk. Meanwhile, McGarrett learns why Catherine left him; and Abby continues to conceal her actual mission from Chin and Five-0.moreless
Sang Min, Five-0's sketchy longtime confidential informant, is accused of murder, so McGarrett asks his old friend Odell Martin to defend him.
As Five-0 investigates a double homicide involving marital infidelity, McGarrett and his team recall their disastrous Valentine's Day experiences.
McGarrett's Aunt Deb visits Oahu on a very personal mission. Meanwhile, Five-0 investigates when some unstable Japanese World War II bombs left behind on the island are stolen.
McGarrett and Danny attend a couples retreat in Maui to work on their partnership issues. Meanwhile, Kamakona's dangerous past comes back to haunt him.
The brother of a promising local boxer is murdered and the chief suspect is the outspoken reigning champion opponent from the mainland.
Five-0 works with a charming con man to find a killer, after his female partner is murdered on the job. Meanwhile, San Francisco police inspector Abby Dunn helps Chin investigate the murders of five Chinese arms dealers.moreless
On Halloween, Five-0 needs to track down a serial killer inspired by Frankenstein. Jerry asks the team for help when an armed gang raids a blood bank. When Grace lies and sneaks out to a Halloween party, Danny heads out to track her down.moreless
Five-0 investigates the death of a wealthy recluse who is found dead in a remote field with nearly one million dollars in counterfeit bills. Meanwhile, Adam is kidnapped by the Yakuza and is forced to torture one of Gabriel's men.moreless
Five-0 investigates the death of a scuba diver who was killed with a gun found on the ocean floor that was used recently in another murder. Meanwhile, McGarrett prepares to propose to Catherine.moreless
A bomb squad is attacked and the culprit threatens to detonate additional explosive unless arsonist Jason Duclair is released from prison. Meanwhile, Adam returns from the hospital and Kono realizes they are being watched; and McGarrett prepares to take his relationship with Catherine to the next level.moreless
Season 6 begins with Five-0 investigating a centuries-old Oahu palace raid involving pirates, buried treasure and a killer who is using a stolen painting as a map. Meanwhile, Kono and Adam are threatened and tortured by Gabriel; and Danny shows concern for Steve regarding Catherine's return to the island.moreless
Season 5 ends with Five-0 learning that a stolen nuclear bomb is somewhere on the island and is about to be detonated. Meanwhile, McGarrett is stunned when Catherine returns to Hawaii; and Chin confronts Adam about his lingering connections to the Yakuza, on the eve of Adam and Kono's wedding.moreless
Kono fights for her life when she encounters rough weather while on a solo catamaran trip around the Hawaiian islands. The journey is something her mother always wanted to do but was never able to experience.moreless
Five-0 helps sober up three married men and sort out the events of their wild night to find who killed the woman found in their hotel suite. Jerry witnesses a woman’s kidnapping off the streets of O'ahu.moreless
When an Elvis impersonator is killed and his body stolen, Five-0 is on the case after it's discovered the culprits are after the hidden diamonds sewn into the victim’s costume. Gabriel returns asking for Chin's help in getting off the island.moreless
McGarrett and Odell come under siege in Odell's barbershop when they try to protect a man who is being hunted by a gang. Meanwhile, Jerry is wrongfully accused of committing a series of home invasions.moreless