What book does Kevin carry around in his backpack In freak the mighty?

Freak the Mighty by Rodman Philbrick does not mention Kevin carrying around a book in his backpack. In the novel, Kevin Dillon, also known as Freak, is a physically challenged boy with a bright mind. He befriends a larger boy named Maxwell Kane, dubbed Mighty. The two form a strong friendship and often engage in adventures and imagination-fueled escapades. The book delves into their personal growth, struggles, and the bond between friends.