Each Hidden Passage

In 1942 France, the unoccupied "Zone Libre" was anything but free. 

Oliver Carmichael has settled into Lyon after his hurried escape from occupied Paris. He owns his own cabaret and directs his own band. But his destiny is not his own, when a French bureaucrat uses Oliver's past to coerce him into meeting with an agent of the Free French. 

Frank Dryden at the American embassy enlists Oliver in the "secret war" against the Vichy regime. Oliver teams up with his friends in the Resistance to undermine the regime and prepare France for liberation from the Fascist forces allied with Hitler. But a fanatical captain of the paramilitary SOL is determined to find out what Oliver and his friends are doing, and stop them at any cost. 

If you enjoy Alan Furst's Night Soldiers novels, but like to see LGBT characters in fiction, then you'll love Each Hidden Passage.