Writer Anthony Horowitz has gone all John Le Carre and retooled Foyle's War now that the war has ended.
After returning from the USA. Foyle is approached by the MI5, now staffed by many Special Operations Executives including Hilda Pierce a person Foyle has come across previously.
The episode begins with some nuclear testing out in the western desert in America. In this atomic post World War 2 age. MI5 suspect that a Soviet spy ring is operating in Britain and his ex driver Sam might be involved somehow.
This is the reel that hooks Foyle. He reluctantly accepts to clear Sam.
Sam meanwhile is a driver for a renowned anti communist scientist and her husband plans to be selected as a Labour candidate in a by election.
Foyle also comes across an ex colleague who has returned from the war and finds that life has moved on without him. His wife now works, his son has grown up and there is no job waiting for him in the city police force.
The pacing of this story is really slow, it does thankfully come together at the end. It is however a greatest hits compilation of a lots of other espionage stories in print and film. Even the story of the returning soldier with no prospects, I can think of James Cagney in The Roaring Twenties being in a similar predicament.