After falling ill during interrogation, Marston is taken to hospital but escapes and is hiding somewhere on his 400 acre hunting ground. When he is found dead however ballistics insists that the murder weapon was the same as that used to shoot Stokes - only that rifle has been in police custody for the last 48 hours. Hathaway realizes that the recent break in at a public swimming pool may have been part of the plot to put someone else in the frame. When one of suspects commits suicide, the body is moved an attempt to make it look like a murder, which leads the police to the killer.
—garykmcd