Haines é um tenista famoso, casado, que gostaria de se divorciar para casar novamente com Anne Morton, a mulher que ama, e que é filha de um senador estadunidense. Para isso Haines viaja até Metcalf, sua cidade natal, com o intuito de conseguir a assinatura do divórcio de sua infiel mulher, Miriam, e fica furioso quando não consegue. Encontra no trem um psicopata chamado Bruno Antony, que o reconhece dos jornais e sabe de toda sua história. A certa altura, durante a viagem, Bruno propõe um pacto: ele mataria a mulher de Haines e em troca Haines mataria o pai dele. Embora Haines não tenha aceitado, Bruno realiza a sua parte e insiste em cobrar o pacto de Haines.
The "strangers on a train" are Guy, a successful athlete in an unhappy marriage, and Bruno, an amoral playboy. Bruno suggests a perfect crime whereby Guy can get rid of his wife without being suspected, and he convinces himself that Guy has agreed to it.
Bruno is obviously evil, but what about Guy? Is he is respectable as he claims? Is his wife that bad, or is Guy really a social climber who wants to be rid of his unfashionable spouse in order to acquire a trophy wife? Does he send mix signals to Bruno because he really wants Bruno's plot to succeed? The notion of hidden, shadowy evil is what gives this thriller its power.
Tennis pro "Haines" (Farley Granger) is quietly travelling in the club car of a train when his neighbour "Bruno" (Robert Walker) strikes up a conversation. It all seems innocuous enough, the former man is an accomplished player and it seems to him that this is a fan, of sorts, who just wants some company as he drowns his journey in Scotch. What quickly becomes clear from this chat is that both have people in their lives they'd rather be without. "Haines" is married to "Miriam" (Kasey Rogers) but would far sooner be married to senator's daughter "Anne" (Ruth Roman) whilst "Bruno" desperately wants shot of his overbearing father (Jonathan Hale). How about these two complete strangers carry out a cunningly planned murder each that will solve the other's problem? The athlete is having none of this, but when "Bruno" takes matters into his own hands a bit of menacing blackmail rears it's ugly head before the suspicious police start sniffing around and "Haines" finds himself in quite a spot. This is one of Raymond Chandler's better structured stories with quite an intricate series of layers to it - each more perilous for the hapless, lovestruck and out of his depth "Haines". There develops a palpable chemistry between the on-form Walker and Granger who both manage to keep this story compelling as director Alfred Hitchcock turns the screws gently but firmly on both of these characters. It all comes to an head in a fairground where the dazzling lights, highly pitched music and accumulating sense of panic complete a tautly presented and powerfully scored (by Dimitri Tiomkin) drama that looks at human vice, betrayal and temerity. Trains always provide well as conduits for crime thrillers, and with strong, if sparing, support from the likes of Marion Lorne, Leo G. Carroll, Hitch's own daughter Patricia as the meddling "Barbara" and a short cameo from Norma Varden (before she discovered large, ugly, hats) to add some richness - and diversion - to the machinations, then it might just make you very wary of striking up any conversation with any stranger ever again!
