Foyle is now working in a different new role working for British Secret Intelligence. As the iron curtain falls across Europe, MI5 believe that British atomic research has been infiltrated, and ask Foyle to investigate whether a Russian spy network could be at work in London.
Foyle's War opens in southern England in the year 1940 - which may seem a strangely remote period in which to place a new detective, but the setting turns out to be a means of adding moral and dramatic depth to the storylines.
Christopher Foyle is a police inspector frustrated at being stuck at home investigating provincial crimes during the second world war.
Honeysuckle Weeks is an inspired choice as Foyle's sidekick, a clergyman's daughter posted from the Women's Royal Army Corps to serve as his driver, and she plays the part with an admirable period style.
Foyle's War - The Eternity Ring Synopsis and Schedule