Instant change of tack: Mark’s grin went from boyishly charming to collegially good-humoured, a change as subtle as it was obviously intentional. He set her politely back on her feet and then went to one knee on the basement floor in his good suit to rescue her shoe from the corner it had fallen into. “Sorry, sorry about that, completely my fault,” he said, “like the Americans say—my bad! Annie in the office said I’d probably find you down here at this time of day. She also said I should just put a meeting in your calendar, but I thought I’d try my luck. Everything all right?”

Walden slipped her shoe back on and straightened her blazer. “Fine, thank you,” she said crisply. “Did you need me for something?”

Like it or not, she had to work with this man. The princess catch and the cheesy line were outrageous behaviour, but it wasn’t a crime to be flirtatious, or outrageous; given how he looked and sounded, both of those probably worked for him as often as not. Easiest to think of him as a forty-something variant on his nephew Will: basically unmalicious, basically selfish, basically manageable. To have one’s career overseen by a smiling consultant was perhaps not that dissimilar to finding a demon in a vape detector. Yes, it was irritating. But Walden could handle it.

“Let’s walk and talk,” said Mark. “Or have you got a club to run now? Year Eight rugby? Year Ten knit and natter?” Two different feints, joke-shaped but not joking: Not a team player, are you, he was saying, not the motherly type either; what are you?

“Year Thirteen Oxbridge interview prep, usually,” said Walden, “but in the magical faculty we rotate it among the Heads of Department. So I have half an hour, if you’d like to meet.” She smiled at him. I’m extremely good, you wanker, was the answer, and he returned her smile with genuine enjoyment, understanding perfectly.

Mark admired her office. “You can feel the history, can’t you?” He admired her big, old-fashioned, green-leather-topped desk. He peered at the antique wall clock. “I’m surprised it’s not possessed,” he said. “These old magicians’ clocks usually are, you know.”

“It was,” said Walden.

“Ah,” Mark said. “Thaumic vacuum when the big one made its move?”

Oh, so he did know something. Walden supposed you could not get away with acting as a magical consultant to the government if you were a complete fake. “Thaumic vacuum, extremely rapid,” she said. “Straight through two layers of defences. The major incursion wards held on in this half of the building, but the demon just went under them.”

“You must have been spitting nails.”

“Excuse me?”