Steve McGarrett is summoned home to the island of Honolulu to bury his father after he is murdered by a madman. Governor Jameson wants Steve to head up a new elite police unit and she will give him full authority to get the job done. Initially he turns down the job, but when he meets the man in charge of the unit, he changes his mind.
Following the abduction of a former NSA cyberterrorism expert, the team must rescue the man and prevent a breach of national security.
An escalating gang war spills into the stands of a high-school football game, killing several people; an unlikely partnership arises.
A violent convict escapes from prison and kidnaps a young couple on vacation; McGarrett's estranged sister comes to town.
When the daughter of the U.S. ambassador to the Philippines is found dead, the governor tasks Five-0 with finding her abducted sister.
When the CEO of a successful surf company is murdered, Kono revisits her past; Five-0 is thrown into the varied but interconnected worlds of North Shore surfing.
When a Navy SEAL, who's on the run for a murder he swears he didn't commit, takes hostages and safe haven aboard the U.S.S. Missouri memorial battleship, McGarrett must use every SEAL skill in his arsenal to diffuse the situation.
When Danny's ex-partner is found dead at a Hawaiian luau the Five-0 team's investigation leads them to some dirty cops and a powerful cocaine cartel.
When a member of the security detail for an upcoming Aid Summit is murdered before he can reveal the details of an assassination plot, Five-0 is brought in to investigate the murder and protect the target, a ruthless dictator.
Five-0 is baffled when a highly skilled ring of thieves pulls off a heist of an armored car, killing two security guards but leaving the money behind. Their only lead in the case requires Danny to reluctantly ask his ex-wife for a favor.
The wife of a newlywed couple is found disoriented with amnesia in Kahana State Park with the husband currently missing. The mother of the husband suspects the wife for staging the whole thing although Five-0 & M.E. Bergman may have discovered a potential newlywed serial killer.
It's Christmas in Hawaii, but instead of celebrating, Five-0 is negotiating a hostage situation when the man who killed McGarrett's father resurfaces. The murderer, Victor Hesse, threatens to detonate an explosive that he's strapped to Chin Ho's chest.
McGarrett discovers new clues in his mother's murder when his sister is kidnapped.
After a high-speed chase, the team makes a gruesome discovery; Chin Ho and his ex-fiancee are awkwardly reunited.
Five-0 struggles to stay a step ahead of a major tsunami that has the island evacuating its shores as they investigate the disappearance of the head of the Tsunami Warning Center.
When the sole witness in a high-profile murder case disappears, Five-0 must head into the jungle to locate and protect her from assassins who are closing in fast.
Five-0 is first on the scene when a pirate attack turns an afternoon pleasure cruise into a kidnap-and-ransom nightmare for a group of wealthy spring breakers.
While Five-0 races to stop a mad bomber before he kills again, Danny gets an unexpected visit from his little brother, Matt, a fun-loving, Wall Street broker. The family reunion is cut short, however, when Danny discovers the real reason that Matt is in Hawaii.
Five-0 combs a convention to find the killer of a sci-fi fan who was thrown out of a high-rise window. A CIA agent who's interested in the Yakuza that killed McGarrett's parents shows up in town to meet with Steve.
While hiking in a remote area of the jungle to see the famed petroglyphs, McGarrett and Danny instead find a homicide victim. Meanwhile, their aunt's failing health leads Kono and Chin Ho to visit home, where Kono finally learns the truth about the scandal that ended her cousin's career with the Honolulu Police Department.
When a crime lord moves against the family of an undercover NYPD detective who infiltrated his organization, it's up to Five-0 to stop the policeman from exacting revenge.
It's the worst kind of overexposure when world-renowned photographer Renny Sinclair is murdered while on assignment in Hawaii shooting the annual swimsuit edition of a top sports magazine.
With the invaluable information that was shared by Agent Jenna Kaye, Five-0 is closer than ever to capturing Wo Fat. Their mission takes an abrupt turn, however, when Danny is exposed to a lethal neurological agent that presents an even greater threat: bio-terrorism on the island.
When Five-0 gets too close to the truth about Wo Fat and his associates, the criminal mastermind retaliates by trying to destroy the team. They've always played by their own rules, but when the Governor can no longer protect them, it's time for Five-0 to pay the consequences of their actions.
Steve McGarrett returns home to Oahu, in order to find his father's killer. The governor offers him the chance to run his own task force (Five-0). Steve's team is joined by Chin Ho Kelly, Danny "Danno" Williams, and Kono Kalakaua.