Jerry is undercover as an orderly at a psychiatric hospital. A patient attacks him with a fork. He's there because a patient. Ben Pollard, was found dead outside the hospital, and Jerry volunteered for the assignment. McGarrett talks Jerry through his doubts. Tani goes to visit Koa, who has been offered a job as a counselor at the rehab center where he was a patient. Duke steals evidence, after tasing a fellow officer. Jerry gets into the dead patient's room by offering to pack up his stuff.  Duke's daughter Carrie confesses to McGarrett and Tani that her daughter Akela was taken by masked men. Duke needs to find a key for the kidnappers. Jerry plays with Ben's former chess partner,  Harris Stubman. Ben's TV was missing, so Jerry checks with the patients in the common room, where the group TV is. A patient told Jerry that another patient, Kosaki, got angry with Ben the day he disappeared. Kosaki threatens Jerry after Jerry tails him. Junior tracks Duke's burner phone to Waikiki Beach. McGarrett and Danny find Duke locked in his trunk. Duke said the key went to a storage locker, in which was a bag of money. Somebody other than the kidnappers stole the money. The key was taken off an arrested drug dealer. Grover convinces the dealer's lawyer to give up the stolen money, and Grover and Tani retrieve it. Jerry breaks to the office to retrieve Kosaki's record, but Kosaki is really dead. His identity has been taken by Dylan Shu, an FBI fugitive. Another orderly, Don, is working with Shu, and pulls a gun on Jerry after Jerry admits he's with Five-0. They make Jerry drive, but he drives into a dumpster and knocks out Don and Shu. At the exchange, Duke gets winged, but the team rescues Akela.