The bodies of two buried men are found and despite persistent attempts, they cannot be identified. When another man is murdered they discover new evidence that soon leads them to an Islamist terrorist cell.

JW is serving hard time in prison and struggling to get back on an honest path. There are glimmers of hope in his life – some venture capitalists are interested in a new piece of trading software he's developed, and while behind bars he's made peace with an old enemy. This all proves to be an illusion. On leave from prison, and back in contact with his former gang, JW learns that once you've walked in the shoes of a criminal there just may be no going back.

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.