Bullied by his siblings and nagged by his parents, 11-year-old Preston Waters is fed up with his family — especially their frugality. But he gets his chance to teach them a lesson when a money-laundering criminal nearly bulldozes Preston with his car and compensates the boy with a blank check. Preston makes the check out for $1 million and goes on a spending spree he'll never forget.

A tough police sergeant's mother comes to visit him, and promptly starts trying to fix up his life, much to his embarrassment. For his birthday she buys him a machine gun out of the back of a van, and begins to further interfere with his job and love life, eventually helping him with a case he's on.