Sabotage

Suddenly, London goes dark and loses all of its electricity. There is commotion at a cinema, with people demanding their money back. The owner of the cinema, Karl Verloc (Oscar Homolka), enters through a back entrance to the living quarters above, and pretends to have been asleep and not know anything of the blackout. His wife, Mrs. Verloc (Sylvia Sidney) comes to get him and is surprised to see him, but he informs her that he had been sleeping the entire time. He instructs his wife to return the money to the customers – against her protests – because he has "some money coming in." As the money is about to be disbursed to the customers downstairs, the lights go back on. It is revealed that sand was put in the Boiler (power generation) as an act of sabotage on London's electricity grid.