This Man Is Dangerous  This Man Is Dangerous (U.S. title: The Patient Vanishes) is a 1941 British thriller film, directed by Lawrence Huntington and starring James Mason and Gordon McLeod. The film is based on the novel "They Called Him Death" by David Hume. This film was long thought entirely lost, but a dubbed Italian version has been traced. Having named the film on their "BFI 75 Most Wanted" list, the British Film Institute subsequently screened a discovered American reel of the film under its American title of 'The Patient Vanishes' in 2017 at its Big Thrill event - the first time the film had been shown on reel in the United Kingdom in seventy years. Mick Cardby (Mason) earns a living as a self-employed private detective, to the exasperation of his father, Detective Inspector Cardby of Scotland Yard (McLeod), who would much prefer his son to enrol as a regular policeman. A policeman is killed while on duty in Hyde Park and Scotland Yard are keen to catch the killer of their colleague. Mick launches his own enquiries, which lead him to Lord Morne (G. H. Mulcaster) who is frantic with worry as his daughter Lena has been abducted by a gang of blackmailers. Lord Morne offers Mick £1,000 to recover Lena safely. Mick gets to work and, aided by his secretary Molly (Margaret Vyner), tracks down the kidnappers to a shady nursing home in a remote rural area. However they manage to flee with Lena to North Wales. The kidnappers arrange a ransom drop with Lord Morne, but Mick arranges for him to go into hiding and goes to the rendezvous himself in disguise. His deception is uncovered and he is overpowered and taken to a derelict cargo ship. The gang use torture to try to get him to reveal Lord Morne's whereabouts, but Mick keeps his nerve and refuses to divulge the information. Finally they throw him into the ship's hold and set the vessel on fire. Mick manages to escape in the nick of time, and also rescues a member of the gang who had apparently been deemed surplus to requirements and had also been left to die on the blazing ship. This man is understandably disgruntled by his treatment at the hands of his former partners in crime, and is only to happy to help Mick out with the location where Lena is being held. Mick makes his way to the hideout and approaches stealthily, but not well enough to avoid being spotted by a lookout.