- Scene: Greenwich Village on a hot summer morning. L.B. Jefferies is taking a nap in the oppressive heat. He's in a wheelchair, in a cast from his toes to his hip. Looks mighty uncomfortable.
- The camera pans across Jeff's apartment, showing us through shots of a smashed camera and a photo of a crashed car that he's a photographer who's had some kind of mishap.
- It pans across the apartments visible from Jeff's window, introducing us to the various activities of his neighbors.
- Jeff is in his wheelchair at the window. He takes a call from his editor: his cast is due to come off in one week, and he's stir crazy after six weeks of recuperation.
- His broken leg is a result of an accident he was in while trying to get the perfect shot at a racetrack for his editor.
- Jeff watches his neighbors from his window, noting the various domestic dramas unfold.
- Stella, Jeff's visiting nurse, shows up to check on him. Stella just knows that there's going to be trouble with all of the snooping on the neighbors.
- They begin to discuss Jeff's fears around marrying Lisa. Stella thinks he's nuts.
- Jeff is afraid that Lisa is too high-maintenance for him. Their lives are just not compatible.
- Jeff fantasizes about Lisa, and we suddenly realize that she's not just a fantasy. The drop-dead gorgeous and very real Lisa has arrived.
- We learn a bit about Lisa's glamorous lifestyle: she's spent a large amount of money getting dinner delivered from one of the best New York restaurants and setting up a romantic evening. She's been running around all day setting up interviews and hanging out with celebs.
- Lisa discusses the possibilities of a life together with an extremely reluctant and increasingly irritable Jeff.
- While Lisa prepares their meal, Jeff watches his neighbor Miss Lonelyhearts pantomime the motions of a date, all alone.
- Jeff compares Lisa to Miss Torso, the ballet dancer neighbor who's currently entertaining an adoring throng of young men.
- Lisa continues to be sweet and entertaining, and Jeff continues to verbally degrade her and her efforts. He's kind of a jerk that way.
- Lisa and Jeff sit together after dinner. Lisa can't understand why Jeff is so sure she couldn't fit into his pre-accident adventurous lifestyle.
- Jeff continues to demean her, and he tells her to shut up rather than address her questions.
- Lisa says goodbye, and Jeff asks why they can't just keep things as they are. Lisa is not sure, but she relents and agrees to return the following night.
- After she leaves, Jeff hears a scream and a crash from a neighboring apartment, but everything is dark and the noise stops.
- Jeff awakens to the sound of the rain a few hours later. He notices the neighbors who have been sleeping on their fire escape scrambling to get their mattress inside.
- Jeff sees his neighbor, a jewelry salesman with a sick wife, leaving his apartment with his sample suitcase at an unusually late hour. Ninety minutes later, the salesman (whose name we later learn is Lars Thorwald) returns with a noticeably lighter suitcase, and he departs a few moments later with the same suitcase, clearly heavy again.
- Jeff is again startled awake, this time by Miss Torso's return from what seems to have been an unpleasant date. The rain continues to pour, and Thorwald enters his apartment with the same suitcase he has been making trips with all night.