Nazi spies infiltrate a British film studio with the intention of sending coded messages in the films they produce.

The Theatre Royal is a struggling London venue battling to keep its doors open. When the bank threatens to close it, the workers fear that they will soon be forced out of their jobs. The Royal's property master, Bob Parker (Bud Flanagan), recruits the rest of the staff to stage a benefit gala. They hope their show, featuring songs and dances, can raise enough cash to stave off the end. Meanwhile, they seek investors who can keep the Theatre Royal and its staff in business permanently.