After Steve receives a posthumous letter from his mother that contains a cypher, Danny is attacked by someone willing to kill to steal it. Five-0 must help Lincoln Cole, an anonymous good Samaritan who’s in the crosshairs of some very dangerous people.

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.