The story revolves around Montgomery Brewster, a poor man who inherits a large sum of money. However, there is a catch — he has to spend every penny within 30 days, and end up with nothing at that time. Should he make the deadline, he stands to gain an even larger sum; should he fail, he remains penniless.

Brewster finds that spending so much money is more difficult than he first thinks, especially when the lawyers are trying to make him fail so that they can claim the money. What makes it worse is that he starts to be a little too successful with some ventures, actually making money from them.
Can Brewster empty his pockets in time for the deadline, or will he end the book as he started it, with nothing?