We first see the all important cigarette lighter just a few minutes into Alfred Hitchcock’s 1951 thriller Strangers on a Train (which was based on Patricia Highsmith’s superb novel) when tennis pro Guy (Farley Granger) meets fan Bruno (Robert Walker) on a train journey and Bruno pockets the lighter (which is inscribed A to G) after Guy leaves it behind.
Before that point the somewhat strange Bruno has already come up with a bizarre suggestion to Guy, knowing that the tennis player is keen to divorce his wife so that he can marry his new love, Bruno suggests they should swap murders – he could murder Guy’s wife and Guy could murder Bruno’s domineering mother.
Obviously Guy brushes off Bruno as something of a crackpot but Bruno is determined to stick to his half of the deal and does so – even going so far as to plan to frame Guy by leaving his lighter at the murder scene. Unfortunately Bruno drops the lighter down a storm drain and desperately needs to get it back. At the same time Guy is competing in a high profile tennis match which Hitch cross cuts to extensively as Bruno thrusts his arm deep into the drain to try and grasp the lighter.
What makes the scene so clever both from the point of view of Hitchcock’s direction and Robert Walker’s brilliant performance is that, as the tension builds, we are actually rooting for Bruno to retrieve the lighter – but if he does of course it will incriminate our hero! A superb example of viewer manipulation in fact.