This beautifully illustrated picture book biography tells the story of Peter Mark Roget, the brilliant but shy boy who grew up to create the world's most famous thesaurus. It follows Roget's lifelong fascination with words and lists, showing how he turned his personal coping mechanism into a revolutionary reference book that has helped millions find the perfect word for over 150 years. Through his story, readers discover how one person's passion for organization and language can change the world of communication forever.