The Return of the Rat (1929)

The rich, amoral Zelie is married to Pierre Boucheron, "The Rat" - but her interest in another man is an open secret. Forced to defend his honour, the Rat takes refuge in his old domain of the Paris underworld. But even here he has a rival - and when murder is afoot, the sinister Morel's ambition threatens to cost the Rat dear....