Five-0 must work with charming con man Hank Weber to find a killer when his female partner is murdered on the job. Also, San Francisco Police Inspector Abby Dunn comes to O’ahu and works with Chin to investigate the murders of five Chinese arms dealers.

Five-0 goes back to school when a college professor is killed and Danny goes undercover as his replacement.

The brother of a promising local boxer is murdered, and the chief suspect is the outspoken reigning champion opponent from the mainland.

A special personal mission sends McGarrett's Aunt Deb to Oahu. Unstable Japanese WWII bombs hidden on the island are stolen.

As Five-0 investigates a double homicide involving marital infidelity, McGarrett and the team recount their disastrous Valentine’s Day experiences.

While Danny’s mother is questioned by the FBI, McGarrett partners with a young man with autism who may have information to help solve the murder of his only friend.

McGarrett and Five-0 must track down a Russian spy who has stolen a flash drive containing classified NSA information that puts the life of a member of their Ohana at risk. Also, McGarrett finally learns why Catherine left him, and Abby continues to conceal her actual mission from Chin and Five-0.

When a man is found left for dead drifting off the coast of Oahu, Five-0 uncovers a deadly slave trade operating aboard an illegal fishing vessel. Also, while Danny is out with his children, his car is stolen so he commandeers a bus to chase down the thieves.

When a woman is murdered in her home, Five-0 learns that one of their own has a deep connection to the victim’s young daughter.

Trapped inside a dilapidated building in Oahu’s Chinatown, Five-0 must protect a wounded Gabriel and plan their escape when enemy gunmen storm the building looking to kill him and anyone who gets in their way.

When the bodies of two serial killers are found on Five-0 property with chess pieces in their mouths, McGarrett and the team hunt for a vigilante as fear grows that tourists aren't safe in Hawaii.

McGarrett risks his life when Five-0 attempts their most dangerous rescue yet of young girls trapped in the sex trafficking ring they have been tracking this year. Also, Kono, deeply affected by the case, makes a life-changing decision.