“It was because of the hag that he knew what conditions would make it possible for him to get to Elphame. Timing was important. Midnight, midday, sunrise, and sunset were the witching hours--never actually an hour long--when the boundary between worlds thinned. The ebb and flow of Elphame's natural magic made the boundary porous for seconds or minutes, during which one could cross over from one realm into the next...”