The Paris Spy by Susan Macneal

 After I read the last in the Maggie Hope series, I thought I should try to find one of the earlier books. The Paris Spy was available, so I started there. In this installment, our intrepid heroine Maggie is undercover in Paris during WW2 trying to find another agent, Erica, who has gone off the radar, as well as her half sister. Maggie is masquerading as an Irish girl in Paris looking for a trousseau for her upcoming wedding. She runs into her friends Sarah and Hugh, who are also in Paris on a secret mission for the government. When they, and Maggie, get into trouble with the Gestapo, Maggie has to use her wits to get them out of Paris. It's quite the nail-biter.