Johnnie is a would-be songwriter; Newton is a would-be inventor. Both work at a cigar stand in the lobby of an office building. Johnnie wants to sell a song to Winfield Lake, a song publisher and the owner of the building. Lake's secretary, Mary, is Johnnie's sweetheart. When Lake turns up dead, circumstances conspire to make Mary and Newton think that Johnnie is the killer. They conspire again to implicate Mary, who goes to jail. But who really shot Lake? Who is the Black Widow, the blackmailer who had threatened him? The other characters in this wacky murder mystery are: Lake's suspicious wife, a self-satisfied private detective, a seemingly slow-witted janitor, Lake's auditor, a songwriter who thinks Lake is stealing from him and another who thinks everyone is stealing from him. It's up to Newton and his truth machine to reveal the real killer.