Suffolk runs into trouble at sea attempting to help a group of environmental activists, protesting against the shipment of nuclear waste. Things get heated aboard the activists' boat after a fracas between Buffer and a crewmember. Shockwaves are felt throughout the Royal Navy when the press take up the story. As a result Buffer faces losing his career.

Mickey is undergoing psychological assessments on shore, but still seems set on a path of self-destruction - until Rosie saves him from yet more trouble and he reveals the truth behind the trawler rescue. Freed of his burden Mickey successfully retakes the DRIU test and is allowed to return to Suffolk.

Dave and Teresa's relationship moves up a gear when, much to Andy's horror, they agree to get married.