In the cold, dark waters off North Korea a U.S. Navy fast attack submarine meets with a mysterious disaster - it's attacked and nearly sunk by an ominous stealth submarine resulting in the deaths of the Executive Officer and the Engineering Officer.
With his wife Elizabeth on life support after a boating accident, Hawaiian land baron Matt King takes his daughters on a trip from Oahu to Kauai to confront a young real estate broker, who was having an affair with Elizabeth before her misfortune.
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.