Under Cover (1916)

At her godmother's place in Paris, Ethel Cartwright meets dashing Stephen Denby but is reluctant to reciprocate her interest in her because he seems to be idle. Denby is actually a jewel smuggler and sells a $200,000 pearl necklace. Upon her arrival in New York, Ethel notices that her necklace is gone and claims her insurance money. The insurance company inspector finds Ethel's sister's behavior very peculiar and has her investigated by customs inspector Taylor; she soon reveals that she is the thief. Taylor tells Ethel he can forget the whole story if she helps him frame Denby. Ethel agrees and does it. As he is about to be taken to jail, Denby offers Taylor $30,000 to release him. Taylor accepts. Denby reveals himself a secret service agent in charge of catching a customs inspector who has been dealing illegally with smugglers for three years: Taylor. Ethel eventually marries Denby.