Bulldog Drummond. Hero, patriot, sportsman and quintessential English gentleman. An army officer in the First World War, he knows how to fight hard and play fair and there is not much that can shake him. Finding peace unbearably tedious he puts an ad in the newspaper offering his services to any client who can offer adventure.

An attractive young woman called Phyllis contacts him fearing for her father who seems to be under the power of blackmailers. Without hesitation Drummond accepts the commission and starts to investigate and uncovers a plot that threatens not just Phyllis and her family but the country itself.