He watched all kinds of plays and ballets from a secret spot up high. A chapter book for fourth grade and up, but a wonderful story for anyone. The Fire Cat by Esther Averill. Pickles is a cat who likes to chase smaller cats. He is not a bad cat, but he is not a good cat.
Pickles is a big cat who wants to do big things.
One day he climbs a tree and has to have help to get down. A fireman rescues him, and decides to take him to the fire house. From then on, Pickles is a fire cat. I Can Read book, level 1. Easy enough for beginning readers.