During show-and-tell, Matthew is disappointed that he doesn't have anything exciting to talk about. Then he thinks of something: "I have a lion!" he tells his class. Everyone is excited about Larry the lion, and the more Matthew tells them, the bigger his story grows. The trouble is that's exactly what Larry the lion is - a story.
When the class proposes a field trip to Matthew's house to see Larry, Matthew has to think fast. Luckily, he comes up with a way to use his wonderful imagination creatively, turning an imaginary lion into a real book.