The Hitchcock Players: James Stewart, Rear Window

Hitchcock was fond of the locked-box mystery, but never in the obvious form: whether it’s the leads in Rope, stuck in their apartment with a body shut up in a trunk, or the survivors from a ship murderously bobbing along together in Lifeboat, the trap was all. James Stewart as LB Jefferies in Rear Window is another man locked in a box, this time kept in his apartment by his broken leg. But clever old Hitchcock – he sets the mystery outside the box.

There is another box too: the one Stewart’s window faces onto, the one whose bottom is a communal courtyard in New York, whose sides are other people’s apartments with squabbling couples, a swinging pianist and a man whose wife disappears. Being a photographer, he knows his way around lenses, and his binoculars and long camera lens implicate us in his voyeurism (another Hitchcock trope) as he spies on his neighbours.

It's a trial run for the sort of myopia Stewart would four years later bring to Vertigo

Stewart’s great triumph in Rear Window is that even with his voyeurism and his paranoia that his neighbour has murdered his wife – he has, but Stewart can’t know this – he does not become an unattractive figure, or rather, he manages to balance these desperate characteristics with zeal and conviction. He’s not a untainted hero, but Stewart keeps us on the favourable side of our sympathetic oscillation.

He sees but he is blind too, of course. When the luminous Grace Kelly, as his girlfriend who persists despite his inattention, enters his apartment, he can only see her as a co-detective. I read this as a nod to his sexual frustration from being laid up (and not being laid): Stewart refuses to treat her as the person she wants to be seen as, and that turns us further away from him. We want to say to Stewart, Look! Grace Kelly is offering herself to you!, but his binocular myopia sends her into harm’s way.

You can see Rear Window as a trial run for the sort of myopia Stewart would four years later bring to Vertigo, but here the psychosexual drama he conveys has a much more naturalistic pitch. Stewart keeps credibility and sympathy even as his paranoia grows, and he keeps us with him as he pushes us away.

• Rear Window is being shown as part of the BFI's The Genius of Hitchcock season on 30 September and 3, 5, 6 and 7 October

Watch a clip from Rear Window