Uniform and CID are on the lookout for escaped prisoner Jim Brodie, so both Brodie's wife and his drug dealer are under observation. PC Nick Slater and WPC Cathy Marshall pursue two burglers down to the riverfront, where one of them gives Slater a severe beating. Marshall sees a person on the barges and gives chase. By the time their backup arrives, delayed by PC Reg Hollis' dodgy belly, Marshall has disappeared. When her dead body is fished out of the river, the two crooks she and Slater had been pursuing are questioned over her possible murder. Searching the barge that Marshall was last seen, CID find evidence that someone has been sleeping rough on board - and it looks like it's their escaped prisoner, Brodie. The river police intercept Brodie fleeing to Amsterdam on his friend's boat, but there is not enough evidence to charge him for Cathy Marshall's murder.