What would you do if you were laid up for eight weeks with a broken leg and couldn't go anywhere? Why, spy on the neighbors, of course!
The entire movie is shown from the point of view from Jeffries' apartment, and is a perfect example of Hitchcock's movie-making genius. Has a murder really been committed? He tells the story by what he shows you with the camera, by what Jeffries and his girlfriend (Grace Kelly) say and do, and by what you see of the neighbors. Hitchcock interjects subtle humor through Jeffries and the various neighbors, such as "Miss Lonelyheart" or "The Newlyweds," but when he decides to turn on the suspense, he turns it on all the way.
I'm not much of a film buff but since reading a biography about Hitchcock I've been trying to watch all of his films - many of which are absolutely amazing, and way better than much of today's movies. Few knew how to tell a story as well as Hitchcock, especially before the computerized special effects we have now. Pay attention to the opening sequence, where he sets up the whole story simply by panning around the room. And watch for Hitchcock's cameo appearance - he often put himself in his movies in clever ways. The version I watched also had an entertaining documentary with extras that talked about some of the challenges, like filming in such a small space. An excellent movie - and well worth your time!