Shortly before the curtain goes up the first time at the latest performance of Earl Carroll's Vanities, someone is attempting to injure the leading lady Ann Ware, who wants to marry leading man Eric Lander. Stage manager in charge Jack Ellery calls in his friend, policeman Bill Murdock, to help him investigate. Bill thinks Jack if offering to let him see the show from an unusual view point, after he forgot to get him tickets for the performance, but then they find the corpse of a murdered women. Bill suspects Eric of the crime, especially, after the second female lead Rita Ross told him she saw the women leaving from Eric's room. Then Rita is shot onstage with Eric's gun. Jack and Bill decide not to stop the show, but Bill preparing to arrest Eric. Is he on the right track ?