“We’ve become a race of Peeping Toms.” So says Thelma Ritter in Alfred Hitchcock’s Rear Window. If she’s right, the movies are partly to blame. This is a movie about watching others – it taps into the very voyeurism that drives the cinema. Ritter plays Stella, nurse to James Stewart’s L.B. Jefferies, a photographer who is confined to his Greenwich Village apartment with a cast on his leg. Jefferies passes the time furtively watching his neighbors across a shared courtyard, including the Thorwalds, a couple whose loud squabbles cease one day when she mysteriously disappears. Could it be murder? Much of Rear Window is filmed through Jefferies’ various spying instruments – his binoculars and, later, a telephoto lens from one of his cameras. Though it is leisurely paced, the picture throbs with tension because each frame holds the possibility of incriminating information. Stewart gives a loose performance that hasn’t a trace of vanity. Jefferies becomes so single-minded he barely notices the considerable advances – especially for 1954 – of Grace Kelly as his socialite girlfriend. Much of the movie’s humor comes from the way Kelly’s Lisa Fremont and Ritter’s nurse are inevitably drawn into Jefferies’ spy game. Lisa, in particular, sees it as a way to prove to Jefferies that she’s more than a delicate flower – especially in the cringe-worthy climax, in which she sneaks into Thorwald’s apartment. That scene and other moments – there is an iconic image of Thorwald (Raymond Burr) sitting in the dark, his cigarette menacingly glowing across the courtyard – conjure up the sort of emotions we normally associate with Hitchcock: suspicion, paranoia, fear. Yet Rear Window is Hitchcock’s greatest movie – and one of the greatest ever made – for the way it echoes the dangerous appeal of the movies themselves. We’re Peeping Toms when we go to the show, and Rear Window sinisterly tweaks the subconscious guilt we feel because of it.