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.

While McGarrett sits in prison awaiting trial for the murder of the governor, Danny brings him a surprise visitor to help clear him. Meanwhile, Kono is suspended from the force, pending an internal investigation.

Chin Ho shares news about Joe White that rocks McGarrett to his core; Danny is forced to play midwife when his ex goes into early labor.

In an update of an episode from the original series, Five-0 tracks a killer targeting cops… and McGarrett is next on the list.

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

On the fourth anniversary of his father's death, McGarrett meets a woman who helps him reopen the last unsolved case his dad worked on before he died.

When McGarrett is kidnapped by Wo Fat, he experiences what would have happened to the team if they had taken a very different path, on the 100th episode.

Danny is abducted and badly wounded by Wo Fat’s wife, who is after the cypher Steve’s mother left him. Steve works to solve the case his father left for him 10 years ago.