Willi Hartung, a German Police Sergeant is shot dead by a gunman during a failed robbery attempt - just one in a sequence of similar crimes. Meanwhile, Jo and Roper investigate the apparent suicide of Corporal Luke Gemmill the driver for Lieutenant Colonel Cosgrove CO of the Wessex Regiment. Forensics prove that Gemmill was murdered - but why was his body found in the luxury car hired from a German ex-soccer star, Kramer. When Sergeant-Major Burns learns that British guns were used in both incidents, he initiates an investigation.
