Lewis Peele, the harbormaster who ran after being questioned by T.C., is holing up in San Diego. Magnum is waiting for him on his boat. He wants Peele to help him find the men who killed Buck Greene. Shammy rolls in for breakfast as Kumu is opening La Mariana the next day. They discover that the koa masks have been stolen. Shammy determines that the thief had hidden in the restroom until after Kumu closed, then left. Rick finds out from an NSA acquaintance that three people involved with the Hadid mission, including Greene, had died recently under suspicious circumstances. Thomas brought Peele back with him to reach out to the killers. Tech recluse Nolan Pierce wants Juliet and T.C. to discover who is harassing him with a drone. Shammy suggests he and Kumu search for the stolen masks. Peele sets up a meet with the killers but Rick has qualms about Magnum's plan. Juliet on horseback shoots down the drone. Gordie picks up the thief attempting to pawn the masks. Kumu meets the boy's mother, who says he stole the masks to pay for her car repairs. Peele gets shot. Magnum chases the shooter while Rick retrieves Peele, who is wearing a bulletproof vest. Thomas captures the shooter, Kane. Higgins finds the drone's launch point. Katsumoto says the prints are from a military prisoner. Kane gives up the kill-squad commander's name, Swayzak. Kumu isn't pressing charges. The four-man team behind the drone was tracking Pierce's pilot, Valentina. The men go after her. Pierce and his staff hide in a panic room. Valentina had tipped off the DEA about a druglord in Venezuela. T.C. grabs handguns from the chopper. They take down the attackers. Rick and Magnum turn over Kane to the U.S. Marshals. Juliet determines the CIA is behind the kill squad.