Sabotage

A Scotland Yard undercover detective is on the trail of a saboteur who is part of a plot to set off a bomb in London. But when the detective's cover is blown, the plot begins to unravel.
Karl Anton Verloc and his wife own a small cinema in a quiet London suburb where they live seemingly happily. But Mrs. Verloc does not know that her husband has a secret that will affect their relationship and threaten her teenage brother's life.