S8E3 : Kāu pahi, koʻu kua. Kāu pū, koʻu poʻo. (Your Knife, My Back. My Gun, Your Head.)

Five-0 enlists the help of an old friend when the boss of a major crime family is murdered, triggering revenge killings across the island. Also, MacGarrett and Danny begin sorting out particulars in their new restaurant venture,