One of Calvin's baby teeth comes out. He looks at it and says he's not entirely comfortable holding a piece of his own head.

Calvin tells Hobbes that Mom told him the tooth fairy might give him fifty cents for his baby tooth. Calvin got an idea to pour plaster over the tooth to make a mold. Now he's casting duplicate teeth. He'll put one under the pillow every night. By the end of the year, he'll have over $150. Hobbes asks if he thinks the tooth fairy will think he had 300 teeth in his mouth. Calvin asks how bright she can be if she'd rather have an old tooth than fifty cents.