That Other Woman in this 20th Century-Fox programmer turns out to be Emily (Virginia Gilmore), faithful secretary to master architect Henry Summers (James Ellison). Hoping to trap her boss into marriage, Emily begins sending "mash notes" to Henry, purportedly from a mysterious female admirer. She then coerces her old pal Ralph (Dan Duryea) to pose as her jealous Southern-fried boy friend of the nonexistent letter-writer. Poor Henry, convinced that Ralph is the gangster who's been threatening him with bodily harm, skeedaddles to parts unknown. Our heroine spends the rest of the picture chasing Henry until he finally catches her.