Hugh "Bulldog" Drummond, a demobilised British captain bored with civilian life, places a personal advertisement in The Times offering his services for "any excitement". One of the many replies intrigues him: Phyllis Benton claims she is in great danger. He immediately sets out for the Green Bay Inn, where she has reserved some rooms for him. Unable to persuade him to give up this mad adventure, his friend Algy Longworth follows after, dragging Drummond's valet, Danny, along. and Ronald Colman in Bulldog Drummond Phyllis turns out to be all Drummond had hoped for: beautiful and desperately in need of help. Her wealthy uncle, John Travers, is being treated in a hospital by a Dr. Lakington for a nervous breakdown, but she is sure there is something wrong about the hospital and Dr. Lakington, and that she is being watched constantly. She runs away when she spots the outline of two eavesdropping men, much to Drummond's annoyance. She is caught and taken to Dr. Lakington's Nursing Home by Carl Peterson, Irma and the doctor. When Drummond follows, he witnesses Travers' unsuccessful attempt to escape. Drummond drives away, but returns stealthily and rescues Phyllis. Sending her off with Algy and Danny, he sneaks back once more and overhears Irma convince the others to stay and try to get Travers' signature on a document transferring securities and jewels to them. Drummond manages to save Travers. However, he makes a serious error when he takes Travers back to the inn. The villains soon arrive there. Drummond manages to disguise himself as Travers; the crooks take him back, along with Phyllis. When they realise they have the wrong man they threaten to torture Phyllis. Drummond tells them Travers is hidden at the inn. While Peterson and Irma go to check, Drummond is freed by Phyllis before Lakington can kill him. He strangles the doctor. Drummond disarms Peterson when he returns, but his gang pose as policemen and take him away. Phyllis persuades Drummond to let them go, telling him she loves him.
of The New York Times called the film "the happiest and most enjoyable entertainment of its kind that has so far reached the screen", and recommended it to those who had harsh words to the burgeoning phenomenon of motion pictures with sound. Hall lauded the film for going beyond a mere filmed version of the stage show, and the "artistry" with which director F. Richard Jones fashioned his scenes with an eye toward humor and thrills. Hall also praised the technical achievement of the sound quality, and the performances of Ronald Colman, Montagu Love and Lilyan Tashman.
