Once again on the eve of his wedding, Captain Hugh Drummond has more pressing concerns when he sets off from London for Spanish-Morocco: his fiancée Phillis Clavering has seen Colonel Nielsen from Scotland Yard being kidnapped by an international criminal gang. Their intent is to force him to reveal the secrets of the British Empire's latest military technology. With his fiancée, chum 'Algy', and valet 'Tenny' Tennyson in tow, Bulldog outwits Scotland Yard's bureaucratic blundering and flies his own plane 1200 miles, only to find more bureaucratic blundering by the local British Consul, who orders him home without delay. Drummond and his friends are not easy to get rid of, however; they soon mount a rescue plan, eventually liberating Colonel Nielsen and throwing the villainous ringleader to his own pet lions.