What could Tom gain if he could retrieve the yellow paper?

The yellow piece of paper and its contents may seem relatively trivial in the general scheme of things, but not for Tom. He clearly thinks it's important enough for him to risk his life to go fetch it. Tom is staying at home one night to do some work while his wife goes to the movies. He wanted to go with her, and he feels kind of bad for sending her to the cinema on her own, but he chooses to stay at home, anyhow. We get the impression that he's a bit of a workaholic, to put it mildly. Tom is desperate for a promotion, and that little piece of yellow paper contains all the painstaking research he's carried out to secure that promotion. He's convinced himself that if he can't retrieve the paper, then his chances of promotion will go up in smoke.