'Single To Paris' is the last fling of SOE operative Rosie Ewing, undercover agent in German-occupied France. She only got out of France on 10th August - 1945 - and now on the 17th she's back in again. Destination Paris, where two other agents, a man and a girl (who not long ago saved Rosie's bacon), have themselves been arrested, are being held in Paris and have information which the Gestapo will go to any lengths to extract.
Also in Paris is a woman by the name of Jacqueline with whom Rosie has had previous dealings and who is now the live-in girlfriend of a highly placed SD officer. Rosie's brief is to find Jacqueline, and through her discover where the agents are being held, then get them out before they either talk or die under torture. But get them out how?