Lucy needs to learn to read and write. Why? It's a secret!
Mom and Dad help her make word-and-picture signs on sticky notes that she attaches to objects. That's what her teacher does in school. For the first sign Lucy draws a picture of Dad, and Dad writes the letters. Lucy sticks the sticky note on Dad's nose, but her dog, Peanut, chews it! Peanut chews all signs--Mom, beans, peas, corn, and more.
After much time and many words, Lucy makes Peanut a vegetable doggy cake, and reveals her secret. She has learned to read and write to make Peanut a birthday card.