Alfred Hitchcock’s 1951 thriller Strangers on a Train follows the story of a tennis star by the name of Guy Haines (portrayed by Farley Granger) after he meets a mysterious man named Bruno Anthony (portrayed by Robert Walker) on the train. After the two have an interesting and “hypothetical” conversation about murder, Guy unwittingly gets himself into a dark and twisted situation where he finds himself fighting to prove his own innocence. Throughout the film, Hitchcock uses light and shadow in order to show the difference between these two men. Guy represents light while Bruno represents dark. To show this Bruno is often shrouded in shadow, while Guy is basically untouched. Bruno is the villain of the story and by way of shadows Hitchcock is able to remind us, aka the viewer, that he is a bad man. The contrast between the two characters is directly tied to the lighting they are given in each frame.
Bars are a recurring motif in the film. They often show up in the form of a shadow that lines Bruno’s face. Bruno is continually associated with these bars. Bars symbolize jail; therefore, the bars that can be seen over Bruno’s face symbolize the crime that he now carries with him. Bruno takes the “hypothetical” conversation between Guy and himself and turns it into a reality when he does “Guy’s muder” for him. By killing Guy’s wife Miriam, he expects Guy to kill his father in return. When Guy refuses Bruno is upset. He follows Guy around like a criminal trying to force him to uphold his end of the “deal”. These bars help to show us that Bruno is in fact a criminal. He is a murder who is figurativly behind bars, but deserves to be put behind literal ones. These shadows of bars foreshadow the truth being revealed, which would end with Bruno being taken to jail. The bars also symbolize Bruno more generally. Bruno is behind bars already despite not being caught yet because he is trapped in his own mind. He is trapped with his own dark thoughts and his desire to ultimately get back at his father for all that he has done to him. Also, in many ways these bars symbolize the way both Bruno and Guy are trapped by their own lives. Guy is trapped in his loveless marriage with Miriam and trapped by his “deal” with Bruno, and Bruno is trapped by the ideas in head of what he wants for himself, despite how unrealistic or unhealthy they may be.
There are also multiple occasions where the film puts Guy and Bruno in contrasting frames that go between Light and Dark. On one occasion Guy leaves the light of his doorway and moves towards the darkness, towards Bruno. While Bruno stands alone on the dark street, Guy moves towards him and as they talk the light still hits Guy’s face and Guy’s face only. Guy wants nothing to do with the darkness, but, in scenes like this you can see Bruno as he tries to literally force Guy into it and away from the light. Bruno wants Guy to join him in the darkness, he wants recognition for his “favor”