David Phillips (Patrick Macnee) is running down the darkened streets of London's Limehouse district, pursued by two men with guns. He finds a public phone and puts a call through to Dick Barton (Don Stannard), but before he can report, a shot rings out. Barton must piece together what Phillips found out that got him killed. Phillips had been assigned to protect Professor Mitchell (Percy Walsh) and his new development, a ray capable of exploding any unstable element aboard an aircraft in flight. Mitchell has been targeted for kidnapping by Serge Volkoff (Meinhart Maur), a foreign agent from Eastern Europe, as part of a larger, much more sinister plot to destroy England and cripple Western Europe. Complicating matters further is that Mitchell's daughter (Joyce Linden) has also been kidnapped, and Barton must contend with Volkoff's crafty female companion Anna (Tamara Desni).

Norman Pitkin and Mr Grimsdale are council workmen mending the road outside an Army base when they come into conflict with the military. Shortly afterwards, they get drafted and fall into the clutches of the Sergeant they have just bested. They are sent to France to repair roads in front of the Allied advance but get captured. Pitkin takes advantage of a useful similarity to impersonate General Schreiber and manages to return a hero

New inmate Rainbow has just been imprisoned for a year for his part in a fight over his girlfriend Wendy. After being assigned to kitchen duty, he becomes involved in a food-trading racket. When the scheme is betrayed to the prison's governor, its prime mover is threatened with an extended sentence - unless Rainbow can come up with a way to save him.