idowed Jean-Francois Mercier is a spy posing as a military atttache in the French embassy in Warsaw in 1937. Leading a double life he may escort League of Nations lawyer Anna Skarbek,girlfriend of Russian emigre Maxim Mostov to a lavish function one night but next day he will be liaising with agent Edvard Uhl,an engineer in a tank factory who brings him blue-prints for a new German tank. Then at night he will lead a covert band investigating secret German tank trials in the forest. The Germans are suspicious of Uhl but he dies before they can arrest him. They do however kill Olga,a bogus countess and spy who introduced Uhl to Mercier. After Mercier is almost caught photographing the tank operations he seeks a new contact in Dr Lapp,a non-Nazi sympathiser who works for a pharmaceutical company. He also begins an affair with Anna. Having helped two elderly Jewish spies to escape Mercier himself becomes increasingly under suspicion by the occupying Germans and,as he goes to put flowers on Olga's grave,is bundled into a car at gunpoint.

Résumé de IMDb.com