Based on Leo Tolstoy's novel, Father Sergius, Night Sun stars Julian Sands as Sergio, a nobleman in 18th-century Italy who is expected to marry a duchess, Nastassja Kinski. Upon learning that she was previously the King's mistress, Sergio turns his back on society and becomes a monk. While at the hermitage he tries to resist all sexual temptations before him and soon becomes known as a miracle worker. Eventually he succumbs to a young seductress and knowing he is undeserving of the adulation, leaves the hermitage to travel around as a homeless beggar.