The year is 1938. Dutch mystery writer Cornelius Leyden (Peter Lorre) is visiting Istanbul. A fan of his, Colonel Haki (Kurt Katch) of the Turkish police, believes Leyden would be interested in the story of Dimitrios Makropoulos (Zachary Scott), whose body was just washed up on the beach. Leyden is so fascinated by what Haki tells of the dead arch-criminal that he becomes determined to learn more.
He seeks out Dimitrios' associates all over Europe, none of whom has a kind word for the deceased. They reveal more of the man's sordid life. His ex-lover, Irana Preveza (Faye Emerson), tells of his failed assassination attempt. Afterwards, he borrowed money from her and never returned.
On his travels, Leyden meets Mr. Peters (Sydney Greenstreet). Later, he catches Peters ransacking his hotel room. Peters reveals that he too had dealings with Dimitrios (he had done prison time when Dimitrios betrayed their smuggling ring to the police), and he is not convinced that the man is really dead. If he is alive, Peters plans to blackmail him for keeping his secret. He generously offers Leyden a share, but the Dutchman is interested only in learning the truth.
Wladislaw Grodek (Victor Francen) is the next link in the trail. He had hired Dimitrios to obtain some state secrets. Dimitrios manipulated Karel Bulic (Steven Geray), a meek, minor Yugoslav government official, into gambling and losing a huge sum, so he could be pressured into stealing charts of some minefields. Bulic later confessed to the authorities and committed suicide. Meanwhile, Dimitrios double-crossed Grodek, selling the charts himself to the Italian government.
Eventually, the two men track Dimitrios down in Paris. Fearful of being exposed to the authorities, he pays Peters one million francs for his silence but, true to his nature, goes to Peters' home shortly thereafter and shoots him. Leyden, his rage over Peters being shot overcoming his fear, grapples with Dimitrios, allowing the wounded Peters to grab the gun. Peters sends Leyden away to spare him from witnessing the violence to come; then shots are heard. When the police show up, Peters admits to shooting Dimitrios and does not resist arrest, satisfied with what he has accomplished. As he is taken away, he asks that Leyden write a book about the affair, and to kindly send him a copy.Sydney Greenstreet as Mr. PetersZachary Scott as Dimitrios MakropoulosFaye Emerson as Irana PrevezaPeter Lorre as Cornelius LeydenVictor Francen as Wladislaw GrodekSteven Geray as Karol BulicFlorence Bates as Madame Elise ChavezEduardo Ciannelli as MarukakisJohn Abbott as Mr. PappasMonte Blue as Abdul Dhris
The novel was published in 1939. Film rights were bought by Warner Bros. The screenplay was assigned to A.I. Bezzerides with Henry Blanke to produce and Nancy Coleman and Helmut Dantine to star. Coleman did not like her role and Faye Emerson replaced her. Dantine was assigned to another film and replaced by Zachary Scott who had just impressed on Broadway in Those Endearing Young Charms; it was his first film.
New York Times film critic Bosley Crowther on its first release gave the film a mixed review, writing, "In telling the picaresque story of a mystery writer on the trail of a Levantine bum whose career of crime in the Balkans has stimulated the writer's awe, the film wallows deeply in discourse and tediously trite flashbacks...To be sure, the Warner schemists have poured some scabby atmosphere into this film and have been very liberal with the scenery in picturing international haunts and Balkan dives...This sort of worldly melodrama calls for refinement in cinematic style, but the writing and direction of this picture betray a rather clumsy, conventional approach."
A Channel 4 review asserts that "the film promises more action than it delivers, but there are opportunities for fine performances by Lorre and, especially, Greenstreet as the master crook. Atmospheric cinematography and an intriguing script turn this into a fine example of film noir with an immensely entertaining cast."
TV Guide calls the movie "One of the great film noir classics to come out of the 1940s, The Mask of Dimitrios boasts no superstars, just uniformly fine talents, a terrific script full of subtle intrigue and surprises, and Negulesco's exciting direction. It's an edge-of-the-seater all the way."
The Mask of Dimitrios was adapted as a radio play aired on the April 16, 1945 broadcast of The Screen Guild Theater, with Greenstreet and Lorre reprising their roles.
The character Dimitrios Makropoulos in Ambler's book is based somewhat on the early career of munitions kingpin Sir Basil Zaharoff.
The assassination attempt involving Dimitrios was based on an attempted assassination of Aleksandar Stamboliyski, the prime minister of Bulgaria. The failed assassination attempt took place on February 2, 1923; Stamboliyski survived it but was murdered on June 14 of that same year.
The film remains relatively faithful to the original novel. Major differences are in the relationship between the novelist and Mr. Peters, which is rather closer than in the novel. When Mr. Leyden attacks Dimitrios at the end, it appears to be partially in outrage at what Dimitrios has done to a person who has almost become a friend. Second, in the novel, Mr. Peters is fatally wounded by Dimitrios, but kills the latter before dying. In the film, Mr. Peters emerges, wounded but alive. He is seen being hustled out the door by the police, having urged the detective story writer to write a book about the case and saying he will have time to read it. Mr. Leyden says to him: "Goodbye, Mr. Peters—au revoir. Sorry you won't be going to the Indies now," ambiguously saying that Peters is or is not likely to recover. Mr. Peters says, "You see? There's not enough kindness in the world." "There's not enough kindness in the world," had been Peters' tagline or slogan throughout the movie.