|Original air date||
1 May 1871
When Straker complains to Henderson that his phone has been tapped he is told that it is to trap a spy within SHADO, who has recently leaked information to the press. When a second leak occurs, evidence points to Foster, who is court-martialled and sentenced to death. Unconvinced of Foster's guilt, Straker discovers that somebody had bugged Foster's flat to frame him and sets out to discover who it is. At the same time Foster escapes and Henderson gives orders for him to be shot on sight.