When Hester Kaplan was just about thirteen and her parents were away for the evening, she entered her father’s study, off limits to her even when he was there. Sitting at the desk where Justin Kaplan had composed his magnificent biography Mr. Clemens and Mark Twain (1966), winner of the Pulitzer Prize and the National Book Award, she turned her father’s typewriter on and off (it made “a satisfying clunk”), played with his paper clips and rubber bands, sniffed his glue dispenser, and spun around in his chair. And then, just as in a Henry James novel, calamity struck —Hester‘s hand brushed against a stack of colored index cards on the desk (the building blocks of her father’s next great work?) and sent them flying across the room; she, watching helplessly as they descended, helter skelter, on the floor. If trespassing into her father’s inner sanctum had been a terrible breach of trust, messing up his notes was the ultimate sin, a crime worthy of harsh punishment: “There would be no way to repair what I’d broken, no way to escape my rotten, destructive nature.”