A ruthless London gang prompts Scotland Yard to recruit retired Bulldog Drummond. He infiltrates the gang with detective Helen, gaining their trust until their true identities are exposed, leading to their capture by the gang overlord.

With a ruthless gang terrorizing London, Scotland Yard calls Hugh "Bulldog" Drummond out of retirement. With the help of detective Helen Smith, Drummond infiltrates the gang under an assumed name. He and Smith become trusted gang-members until the gang's overlord discovers their true identities, and they are taken as prisoners.—Les Adams <[email protected]>