A suicide bomb attack in a nightclub has a shocking impact on the crew of HMAS Hammersley. Dutchy goes undercover with the SAS to capture a group of deadly extremists before they can attack Australian targets. 2Dads risks his life to save Hammersley from a bomb attack. Kate's world is rocked when her former lover, SAS officer Jim Roth, returns to Hammersley. Mike risks his career by refusing to co-operate with a high ranking ASIO spy.