Plum ran. She could have stayed and tried to help, but that would have been compounding her stupidity with more stupidity. She did the hard thing and trusted him: she hurdled the couch like a champion and felt a shockwave as Professor Coldwater detonated some final spell. The force of it lifted Plum off her feet for a second and made her stagger, but she found them again and kept on running.

Going back was faster than going forward had been. She was bounding ahead seven-league-boots-style, which at first she thought was adrenaline till she realized, nope, magic. One stride took her through the hell-room, another and she was in colonial Brakebills, then she was in Wharton’s room, on the roof, in the dining room crawl space, the library, hard left turn at the creepy-pear-tree-courtyard, the passage. The sound of doors slamming shut behind her was like a string of firecrackers going off.

She didn’t stop till she was back in the safety of the Senior Common Room, breathing hard. He was right behind her, just as he’d said. He’d done it, he’d gotten them out. Never had anything seemed so certain than that she was going to die in that room, but now it was over. The bad thing, the horror, had broken out of wherever it had been hiding all her life, but he’d shoved it back down. For now.

Without a word Professor Coldwater set about resealing the passageway behind them. She watched him work, her breath slowly going back to normal, dazed but not so dazed that she wasn’t interested in the technical aspects: moving in fast-motion, his arms flying crazily like a time-lapse movie, he assembled an entire intricately patterned brick wall in about five seconds.

She wondered where he’d learned how to do that. Not here. This time he left out the fancy signature angles. Say that for him: he learned from his mistakes.

Then he climbed out and closed the door. They were alone. It could all have been a dream except for the plaster dust on the shoulders of Professor Coldwater’s blazer.

“How did you know?” she said. “How did you know where I was? Where the ghost was?”

“Not a ghost. A niffin. Very bad news.”

“What did it want?”

“She. She used to be human. And I don’t know. Did she say anything to you?”

“No. Can they talk?”

“I don’t know.” One of his fingers was still crackling with a bit of white fire; he shook it and it went out. “Nobody knows much about them. I’m not even sure I did anything to her. I just distracted her and got out of there.”

“But you looked surprised when you saw it. You looked like you recognized it. I mean her.”

“I know.” Professor Coldwater looked sadder and less triumphant than she would have thought. “I know I did. I wish she’d said something.”