Set during the mid-19th century, the film dwells upon the foredoomed romance between Russian princess Katia (Danielle Darrieux) and the married Czar Alexander II (John Loder). Impressed by her forthrightness and courage, Alexander finds Katia a breath of fresh air when compared with the usual obsequious noblemen who nip at his heels. When their love affair becomes public during a state ball, the ensuing scandal forces Katia to flee to Paris. Upon the death of his wife, the Czar is at last free to wed his beloved Katia-but fate intervenes in the shape of an assassin's bullet.