Alfred Hitchcock is the most famous movie director in history, second only to perhaps Steven Spielberg. Hitchcock was one of the directors for whom the French coined the term “Auteur Theory”. It states that the director leaves an indelible stamp on a film, like an author on a book. This has lead to many, many books and essay on his movies, particularly "Vertigo", "Rear Window", "Psycho", and "Strangers on a Train." The film historian, Donald Spoto, has a good essay on the movie. Consequently, I will not be doing a in depth analysis of "Strangers on a Train."
For this discussion, I would like to highlight two points: the adaption from the book and the Hitchcock character universe.
Strangers on a Train is based a famous book by thriller author Patricia Highsmith. Like most Hitchcock's adaptions, it is very loose. The setup in the book is the same, but the details are different. Guy Haines, the hero, has a different occupation without political aspirations. Bruno Anthony, the villain, has a less refined demeanor.
Personally, I liked the characters in the movie more than those in the book. It just works better for the story. In the movie, Bruno Anthony is well dressed and outgoing. He is also a sociopath. He has his own sense of morality, which is evident in this line from the movie:
"Some people are better off dead, Guy. Take your -- wife and my father, for instance."
In the movie, Bruno meets Guy Haines on a train and sees an opportunity for independence. In his mind, this is a simple transaction of murder and he just wants to get it done. Guy fails to keep up his end of the deal so Bruno tries to coerce Guy without exposing their connection.
In the book, however, Bruno doesn't seem to mind the broken agreement. He has identified Guy as a weak person he can manipulate. This gives him an opening to enter Haines' life and wreck havoc. He shows up so much in Guy's life, it would have been hard to sell that they did not know each other. At this point, the transaction is beyond salvage and Bruno would have been better off turning himself in and blaming Guy for planning it. He doesn't, and he escalates the interactions. The reader gets the sense that Bruno is attracted to Guy and wants to be around him. At the end of the book, Bruno is accidental killed or he kills himself to totally mess up Guy. Guy suffers a total guilt breakdown and confesses to everything. The ending of the movie is more subtle. A Catholic priest innocently identifies Guy on a train, but Guy denies his identity. Bruno is gone from Guy's life, but Guy's paranoia and guilt persist.
There are many movie reviews which make much of Bruno's lifestyle. Bruno is not attracted to any female characters. In all fairness, there are no attractive women in the movie. The character of Guy's wife is repulsive to everyone. The girlfriend is very nagging, the sister is just a child, and other other women are silly. This maybe a cause for misogyny on the filmmaker's part, but not a clear cut case for the Bruno character. To say Bruno is just attracted to Guy is selling Bruno short. Firstly, Guy is a very uninteresting person. Secondly, it oversimplifies the Bruno character. Bruno is much more interesting as a sociopath. A person who has no allegiance to anyone and everyone is in danger of his wrath. Guy is only alive while he is still useful to Bruno, much like Count Olaf from "A Series of Unfortunate Events".
One of the hallmarks of an Alfred Hitchcock movie is the moral ambiguity of the characters. He is known for specializing in “the innocent man” theme of movies. The main character is innocent of the main crime, but none of his heros get away in end guilt free. In "39 Steps", "Saboteur", "Notorious" and "North by Northwest", the hero has to be deceitful and a little ruthless to survive.
His heroes have unlikable traits, and his villains are more charismatic than the hero. Examples of sympathetic villains are found in: "Rear Window", "Murder", "Lodger", and "Shadow of a Doubt". In contrast, unsympathetic heroes are found in: "Rope", "Dial M for Murder", "Marnie", and "Vertigo".
A variation on this theme is that the hero is an outsider and the villain has a place of authority in society. There is usually a confrontation where the villain is believed over the hero. Examples of this are found in "39 Steps", "Saboteur", "Foreign Corespondent", "North By Northwest" and "Family Plot."
For a couple of movies, Hitchcock directly compares the heroes and the villains. Examples of this are:
"Notorious": The hero recruits the heroine for a dangerous mission by manipulating her feelings. During the mission, he suspects the worse and does not defend her. On the other hand, the villain is in love with the heroine and sees a relationship with her as an opportunity to get away from an overbearing mother. Even when the heroine does some questionable actions, the villain continues to have total trust in her.
"Family Plot": The movie has two couples. The hero couple is comprised of crass small time swindlers and the villain couple are suave high class extortionists. Interestingly, the tables turn when each couple adopts the other's behavior.
"Frenzy": The two characters in the movie, Richard Blaney and Bob Rusk, share mirrored initials. Blaney, the hero, is a standoffish loner. Rusk, the villain, is a charismatic member of society who loves his mother. There is a point in the movie where it is the hero's word against the villain's, and everyone trusts the villain.
"Strangers on a Train": The villain is more charismatic than the stiff hero. Hitchcock compares the two in much of the film. At a party, Guy stands around stiffly while Bruno chats with some women he met there. Guy is seen yelling at his wife while Bruno helps a blind man across a street. The two characters are cross cut through much of the movie. There are also many instances of the number two in the movie. It starts with two pairs of feet. On the train, the villain calls for a pair of doubles. There is the doubles reference in tennis and Hitchcock is seen with a double base. It does seem to reinforce the concept of duality he explores within the characters' personalities.