After a bulletin board falls on Stanley Lampchop while he is sleeping, he finds that being flat has its advantages. He's four feet tall, about a foot wide . . . oh, and half an inch thick.
At first being flat is fine. It's fun going in and out of rooms simply by sliding under the door. And it's exciting being mailed in an envelope to your friends in California for a visit. Stanley has many adventures including one where he helps catch thieves from stealing a painting from a museum. But soon Stanley wishes he could be just like everybody else.