In Strangers On A Train, directed by Alfred Hitchcock, two men meet by chance in a train carriage. One (Bruno, played by Robert Walker) recognises the other, Guy (Farley Granger), who is a famous tennis player. Bruno initiates a conversation between them, in which he subtly exposes Guy's insecurities. Bruno then makes a theoretical proposal: that he will kill Guy's unfaithful wife if Guy kills his father. Guy laughs dismissively at the idea, and leaves the train.
Then, when Bruno carries out his end of the arrangement, he pressures Guy to do likewise. Guy refuses, though he realises that he cannot tell the police that Bruno killed his wife because Bruno would claim that they had plotted the scheme together. Thus, Guy is treated as a suspect by the police, and must find some way to stop Bruno from framing him.
The plot, an archetypal Hithcock concept, comes from Patricia Highsmith's novel Strangers On A Train, which Hitchcock adapted with Czenzi Ormonde and Barbara Keon. Novelist Raymond Chandler had been originally contracted to write the script, though Chandler disliked collaborating with Hitchcock. Chandler regarded Hitchcock's contributions as interferences, while, for Hitchcock, collaborating on a script was the most enjoyable part of the creative process.
The novel's central premise remains unchanged in the film; this is unsurprising, as it's such a perfect Hitchcockian scenario. There was a major structural alteration, however: in the book, Guy does indeed kill Bruno's father, whereas in the film he does not. Highsmith's book is about the corruption of innocence: Bruno's pervasive persistence ultimately drives Guy to murder, much as Iago poisons the mind of William Shakespeare's Othello.
Hitchcock's film, on the other hand, explores the persecution of innocence, with an innocent man under constant suspicion (a theme he dealt with equally directly in The 39 Steps, North By Northwest, and The Wrong Man), as Bruno encourages Guy to feel guilty for a crime he has not committed. Other Hitchcock preoccupations are present, too: the idea of the 'perfect murder' is a conversation topic in both this film and Shadow Of A Doubt; also, the 'Oedipus complex' lies at the heart of the mother-son relationships here, in Psycho, and in Notorious.
The most striking element in the film is Robert Walker's performance as Bruno. He perfectly captures the character's decadence, obsession, and psychosis. Indeed, notwithstanding his murder of Guy's wife, he is the most engaging character in the film, and the audience is invited to sympathise with him. Hitchcock's villains were often more engaging than his heroes: Uncle Charlie, for instance, in Shadow Of A Doubt, Norman in Psycho, and Tony in Dial M For Murder. Bruno is also another in a line of Hitchcock's gay characters: while Brandon and Phillip in Rope, Leonard in North By Northwest, and Mrs Danvers in Rebecca are not explicitly homosexual, they are, like Bruno, implicitly coded as gay.
The notion of contrastive doubling is another significant aspect of the film, recalling the two Charlies of Shadow Of A Doubt: two leading men (gay/straight, guilty/innocent), two love interests (Madonna/whore), and two detectives (good cop/bad cop). The psychological subtexts (doubling, Oedipal relationships, transference of guilt) add layers of interest to a thoroughly entertaining and blackly comic film.
Aside from the brilliant performances by Walker (in his only Hitchcock film) and Granger (who had previously appeared in Rope), the supporting cast is also outstanding. Leo G Carroll (veteran of five other Hitchcock films) is superb, and Hitchcock's daughter Patricia (who later appeared in Psycho) has a substantial role. This film also marks the beginning of Hitchcock's collaboration with cinematographer Robert Burks, who would go on to photograph eleven further films for the director.
The standout sequence is before Guy's tennis match, when the spectators' heads turn like metronomes from left to right to left to right, following each volley of the ball, while Bruno stares conspicuously ahead. The ending, however, is less impressive: there is an unrealistic (typically outrageous) shootout on an out-of-control carousel, followed by a studio-imposed coda. Fortunately, though, the ending cannot diminish one of Hitchcock's greatest films.