1943, The Netherlands is under total Nazi occupation. In Amsterdam, Jack, an unassuming accountant, first meets Ina at a birthday party - a 20-year-old beauty from a wealthy diamond manufacturing family who instantly steals his heart. But Jacks pursuit of love will be complicated; he is poor and married to Manja, a flirtatious and mercurial spouse. When the Jews are being deported, the husband, the wife and the lover find themselves at the same concentration camp; actually living in the same barracks. When Jacks wife objects to the girlfriend in spite of their unhappy marriage, Jack and Ina resort to writing secret love letters, which sustain them throughout the horrible circumstances of the war.