The Stars Are Dark — Peter Cheyney

AKA 'The London Spy Murders'
Quayle, the master of a British spy ring in World War II, is faced with the task of dealing with a man who has come from Morocco with what he says is important information about German troops there. But is the man what he seems?Quayle puts his agents into action, not hesitating to risk their lives to discover the answer, but it is Quayle who ends up doing most of the work - and who is prepared to sacrifice everything for the cause of war.