Broadway star Patricia Wallace (Evelyn Venable) quits her Broadway show to run off with wealthy Fred Arnold (Ralph Forbes). Her director Jimmy Hart (Victor Jory) follows them aboard a super-speed monorail, the Streamline Express. Meanwhile, also aboard is John Bradley (Clay Clement) and his mistress Elaine Vincent (Esther Ralston), but Bradley's wife Mary (Erin O'Brien-Moore) ends up on the train as well.