"Duet" is the 19th episode of the American science fiction television series Star Trek: Deep Space Nine. Set in the 24th century, the series follows the adventures on Deep Space Nine, a space station located near the planet Bajor, as the Bajorans recover from a brutal decades-long occupation by the imperialistic Cardassians. In this episode, Major Kira Nerys, the highest-ranking Bajoran officer on the station, finds herself compelled to confront an apparent Cardassian war criminal, who may be lying about his identity.