Steve McGarrett is summoned home to 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.

When a former cyber terrorism expert is kidnapped, Five-0 is assigned to find the missing expert in order to protect national security.

Five-0 discovers a connection between Samoan gangs and a mainland mob after an escalating gang war wreaks havoc during a local high school football game.

Five-0 is called in to locate a dangerous escaped prisoner and to find him they need to determine his reasons for escaping. Steve's sister, Mary Ann arrives from the mainland for a visit and brings trouble of her own.

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.