Vidocq.

François Vidocq has deserted to go back to his wife and kids, so he becomes a thief. Unfortunately, he finds she had become Manon-la-blonde, mistress of a rich man named Ouvrard, and his children have disappeared. He offers his services to the chief of intelligence service and begins a fight against the Aristo, chief of the gang of the children of the sun. After a few years, he dismantles the gang, and finds both his sons. One has become a blackguard, the other a famous organist who is about to be knighted and will soon get married to his beloved.