Harry (of Harry's Visit, etc.) has had bad luck with his library cards: his dog ate one, another failed to survive the laundry, and now he's kept a third so safe that even he can't find it. Surely Ms. Katz., the patient but busy librarian, will not want to make a fourth! Fortunately, like the other adults in Harry's life, Ms. Katz is more interested in helping Harry solve his problem than in blaming him. Gently humorous and impeccably true to life, Porte's story neatly reprises salient facts from the earlier stories--e.g., Dad, widowed, is a single parent. Abolafia's cartoon-like illustrations convey the story's warmth and humor; in an amusing extra mini-story on the page corners, the dog gradually assembles and climbs onto a stack of books.