Rick is between homes so Magnum decides to invite him to stay in the guest house with him. Their new client wants to know why his sister Carina, a recovering drug addict, relapsed and overdosed. They go to HPD to get a look at Carina's case file but run directly in Det. Childs. Higgins asks point blank to see the file and Childs approves. The autopsy photos prove that someone else tied the strap around Carina's arm. Jin overbids for the storage unit he wants. Katsumoto gets Magnum and Higgins in undercover as lifeguards. They meet their supervisor, Cole Graham. Graham says he had picked Carina to be his replacement. JIn got a tip that the unit he bought belonged to a thief who was sent to prison. There is a Purple Heart in the unit and T.C. wants to find its owner. Thomas and Juliet line up suspects. These include some surfing regulars and Sharon, who will now take over when Graham retires. The M.E. found a banned sunscreen on parts of Carina's body, indicating that she may have been strangled. Gordon points out that the man bidding against Jin may have been a member of the thief's crew. Magnum gets caught searching the surfers' van. The surfers downplay their quarrel with Carina. Footage the surfers took showed Carina rescuing someone who runs off. Magnum goes to the man's house and finds drugs inside fish in a locked freezer. They call in Childs. A drop is planned for that day at the Oahu Fish Market. Jin gives up the unit for the veteran's address. Jin had already emptied the unit. Thomas and Juliet take down the seller, against Childs' orders. Graham killed Carina because he was part of the drug-smuggling operation. Buck Greene's body is found.