Someone in the House (1920)

Wealthy Society Was the Prey A HIGH-POWERED MYSTERY PLAY A Diamond Necklace and a Woman's Heart.

Alias "the Dancer," fashionable society crook Jimmy Burke is hot on the trail of the Brent diamonds. Upon learning that Molly Brent and her diamonds are the stars of an amateur play, Jimmy obtains the leading man's part and devises a plan to steal the jewels. Molly falls in love with her leading man, who plans to switch the gems with fakes during the performance. After the play, the police question the couple and Molly declares that the robbery was part of the drama. When she discovers Jimmy's deed, she begins to cry and "the Dancer," realizing that he is in love with his victim, renounces his profession.