Tommy Mooney—a hero after his adventures in Nazi-occupied Europe and wartime Britain—is back at Warfield Hall in England when he gets a call from his friend Daphne. "We've a letter from Paris," she says. "A very odd sort of letter." The letter, written in invisible ink, is from their Parisian friend, begging them to help find her sister Sophie, who has gone missing. There is no way that Daphne is returning to German-occupied Europe. Unless, that is, Tommy can find a way to drag her there.

A mystery involving a stolen masterpiece, communist Resistance members, and a foolhardy attempt on the life of Hermann—the rat-fink—Göring, leader of the Luftwaffe.

Hearkening back to the Hitchcock film, Saboteur, and the WWII era mysteries of Eric Ambler and Helen MacInnis, Letter Via Paris continues a series featuring a truly likable, sometimes irascible, archetypal "everyman" hero.