Halina works as a nurse in a hospital. One day she catches her husband in an affair. Irena, his jealous mistress, decides to get rid of her rival and accuses her of spying. Halina is arrested and sentenced to death, leaving Irena tormented by guilt. The Spy is the oldest surviving film by Aleksander Hertz, one of the pioneers of Polish cinema. It was produced by the Sfinks studio, regarded as Poland’s first film company. As with other Sfinks productions, the cast features the most popular actors from Warsaw’s musical and dramatic theatres. The film remained unknown to the wider public for decades and was long considered lost. Only in 2001 was an incomplete copy with Russian intertitles rediscovered in a Russian film archive.