When the story opens Tom has chosen to stay at home and work on an office memo rather than accompany his wife Clare to the movies, even though they are showing a movie he has wanted to see, and even though he feels a little guilty about disappointing Clare by sending her off alone. As a good fiction writer, Jack Finney knows the value of appealing to all the reader's senses to make his scenes vivid and seemingly real. Notice how he appeals to the sense of smell when Tom says goodbye to his wife.
He kissed her then and, for an instant, holding her close, smelling the perfume she had used, he was tempted to go with her....He gave his wife a little swat and opened the door for her, feeling the air from the buildinig hallway, smelling faintly of floor wax, stream past his face.
Tom does not actually choose to risk his life to retrieve the yellow sheet of paper that blows out the window when he opens the front door for his wife and creates a draft. He tells himself it will be safe and simple, as long as he doesn't look down.
It occurred to him that if this ledge and wall were only a yard above ground--as he knelt at the window staring out, this thought was the final confirmation of his intention--he could move along the ledge indefinitely.
He makes two serious errors in judgment before he climbs out the window of his eleventh-floor Manhattan apartment. One is that he overestimates the width of the ledge. The other is that he does not realize he will be forced to look down when he gets to his precious paper.
He moved on the balls of his feet, heels lifted slightly; the ledge was not quite as wide as he'd expected.
Because the ledge is so narrow, Tom has to shuffle along sideways, hugging the brick wall, grabbing crevices with his fingertips, and resisting the natural temptation to look down. But when he reaches the paper he can't pick it up in a nartural manner. If the ledge were wider he could turn sideways and bend at the waist. But there is no room to turn sideways. He has to keep facing the building and, by bending his knees, lower himself far enough down to be able to reach the paper with his arm extended. In that awkward position he is forced to look down--and this is where he realizes he has put his life at extreme risk.
He saw, in that instant, the Loew's theater sign, blocks ahead past Fiftieth Street; the miles of traffic signals, all green now; the lights of cars and street lamps; countless neon signs; and the moving black dots of people. And a violent explosion of absolute terror roared through him.
This is excellent description, saved for this crucial moment. The moving lights and changing traffic signals, as well as the moving dots of pedestrians, are sure to make him dizzy. The reader's suspense is intensified because the title of the story seems to suggest that Tom is going to be found dead. The author eventually justifies his title with the following insight into Tom's mind:
He thought wonderingly of his fierce ambition and of the direction his life had taken; he thought of the hours he'd spent by himself, filling the yellow sheet that had brought him out there. Contents of the dead man's pockets, he thought with sudden fierce anger, a wasted life.
Tom only chose to stay in his safe and warm little apartment to do some paper work. He ended up facing almost certain death on a cold, windy, precarious perch high above oblivious and uncaring Manhattan.