During 1959 60, Schulz premiered several Peanuts essentials. Snoopy now lounges atop his doghouse rather than in it, Lucy establishes her psychiatric practice, and Linus observes the first of his fruitless Halloween vigils for the Great Pumpkin. Charlie Brown's sister debuts, giving him more to be depressed about ("I thought that having a baby sister would change my whole life, but it hasn't"). What's more, the period includes the famous "Happiness is a warm puppy" strip. Librarians should appreciate a two-week sequence in which Charlie Brown despairs over losing a library book ("You're a dead duck," Lucy tells him). By this point, Schulz's always-appealing artwork has been pared to perfection, and yet he would make it simpler still in decades to come.