Although the First World War is over , it seems that the hostilities are not , and when Captain Hugh " Bulldog " Drummond discovers that a stint of bribery and blackmail is undermining England " s democratic tradition , he forms the Black Gang , bent on tracking down the perpetrators of such plots . They set a trap to lure the criminal mastermind behind these subversive attacks to England , and all is going to plan until Bulldog Drummond accepts an invitation to tea at the Ritz with a charming American clergyman and his dowdy daughter .