The Five-O had to find the only witness to a murder case after the H.P.D officers assigned to escort the witness and the federal marshal protecting her went missing. Assassins sent by the cartel the witness was testifying against killed the marshal protecting her and then followed her into the jungle.
Chin and McGarrett rescued the witness while Kono did research to locate all the assassins sent to kill her. Chin and McGarrett managed to get the witness to the courthouse in time to testify, and Kono managed to stop one of the assassins, acting as the murder's co-council, before the assassin killed the D.A. and the witness.
Meanwhile, Danno was convinced that the carjacking and robbery experienced by his ex-wife, Rachel, and his daughter was linked to something Rachel's husband, Stan, had done. His suspicions were proven correct when Stan confided in him that he had tapes that he was going to use to expose a housing inspector that was extorting Stan over a property deal. Danno confronted the inspector and threatened to kill him if he ever put a gun in the same zip code as his daughter again.