Download 3 Bullets for a Long Gun
Bulldog Drummond hunts down an assassin after a priceless diamond.
While in Geneva, Detective Hugh "Bulldog" Drummond receives a manufactured diamond as a wedding gift, but it is stolen by Sir Raymond Blantyre, head of the Metropolitan Diamond Syndicate of London. The fifteen-carat diamond was made by Professor Bernard Goodman, the father-in-law of Hugh's friend Algy Longworth. It was meant to remain a secret until Goodman could present his process at a Royal Society Meeting and publish his formula in a scientific paper. Hugh and Algy trail Blantyre to London and arrive just after Blantyre and his secretary, Roberts, have tried to intimidate Goodman into selling his formula to them. Undaunted, Goodman calls his American rival, Dr. Max Botulian, whom he has never met, and convinces him to abandon his own experiments in deference to Goodman's success, and lend his larger equipment to him so that he can finally make the largest diamond in the world. Blantyre wants Goodman's formula destroyed, however, and he and Roberts visit Botulian and intimidate him into keeping his own discovery quiet. They then offer him £5,000 to let them keep the nine o'clock appointment with Goodman for him so that they may dynamite the laboratory. Botulian plans to out-think them, however, by arriving earlier than nine o'clock, removing Goodman before the explosion, and having Roberts die in his place in order to get more money from Blantyre. That night, Roberts arrives at Goodman's laboratory disguised as Botulian and carrying a case of dynamite instead of Botulian's equipment. When Goodman's lab explodes and his watch and clothes are found in the rubble, he is presumed dead. The next day, however, a man calling himself Botulian arrives at Hugh's house demanding Goodman's laboratory notes as bequeathed to him in a letter written in the professor's hand. When the apparently real Botulian arrives later that night with the same request, swearing the earlier man was an impostor, Hugh gives him an empty envelope to appease him, and then follows him home. At Botulian's lab, Hugh tells Botulian that he knows Goodman is still alive, as evidenced by the letter's fresh ink. Caught in his lie, Botulian locks Hugh in his lab with Goodman, who, forced to recreate his formula, confesses to Hugh that his notes were burned in the explosion. Meanwhile, Colonel Nielson of Scotland Yard, who had heretofore supported Blantyre's efforts to stop Goodman's work, discovers Roberts missing. At the same time, when Hugh's abandoned car is found, his friends search the neighborhood. Hugh's valet Tenny has himself kidnapped and helps Hugh and Goodman escape just as Phyllis locates Botulian's apartment and is herself captured. Hugh returns to save Phyllis and foils Botulian with a sword as Blantyre arrives and, believing Botulian is Roberts in disguise, throws him his gun. Botulian then confesses to murdering Roberts the night of the explosion and pretending to be Roberts posing as Botulian to deceive the police. Nielson arrives in time to arrest the criminals, and Hugh and Phyllis receive a police escort out of town for a "shot-gun" wedding.