Two men meet on a train and start talking. Unfortunately, one of them is an alcoholic psychopath who proposes a double murder that each could commit on behalf of the other. They would have the perfect alibi of being strangers with no real motivation to perform such a crime. Highsmith expertly ramps up the tension as the two men become progressively more tangled up in each other's lives and the unthinkable becomes reality. It's an intense psychological study that digs into the nitty-gritty of the human soul – examining fear, morality, identity – and you can see why it appealed to Hitchcock enough to make a film of it (in 1951).
I saw an astounding theatrical production of this at the Gieldgud Theatre in London in November 2013 – twice. The set utilised shades of grey in keeping with the noir-ish style, while the highly creative use of film projections over the stage backdrops added depth, motion and flair. The super-dramatic merry-go-round scene will stay with me for a long time.
This original novel ends differently from the play, but the premise is so strong that both versions work equally well.
