After Foyle is a guest at a friend's home at a dinner for an important American diplomat, a suicide victim and German agent both are discovered near the house.

Sam volunteers to go undercover to discover how rationed gasoline is being stolen from a fuel depot, and Andrew becomes a suspect in a murder case.

When a British food corporation signs a secret agreement with the Nazis to provide essential food services to the enemy during wartime, murders result.

Foyle's investigation of the death of a young black marketeer and stolen food is interrupted by his suspension on charges of sedition.