They were still arguing about something, now with Laura in the middle. Two yawning young men with trainee stripes on their sleeves were standing guard over the pathetic tableau of Nikki, Mathias, and Will. Mathias was fidgeting compulsively with the edge of the foil blanket over his lap. Will seemed to have given Nikki his school hoodie.

“—not possible!” said a Marshal Walden didn’t recognise, spitting it at Laura. His rank insignia suggested he was a district commander. Wonderful.

“Would you kindly explain,” she said, in her coldest and most schoolmistress-ish voice, “why you have chosen to keep these children sitting on the ground in the cold in mid-October?”

She saw the tone hit. The district commander flinched. It did occasionally happen that you triggered someone’s long-suppressed memories of getting told off at school, and Walden wasn’t above taking advantage. She raised her eyebrows at him, giving off her best impression of detention imminent. “Uh—is it Miss Walden?” said the Marshal.

“Doctor,” said Laura.

“Dr Walden … we have to keep them all under formal observation,” the Marshal said. Rallying a bit, he added, “You as well. In case—”

“I see,” said Walden, even more coldly. “Is there any particular reason this observation has to take place here?”

The district commander admitted, in a mumble, that there was not, and suggested vaguely that the district barracks in Milton Keynes …

Walden shut that down firmly. “Since you and your squad aren’t DBS checked—in fact, I’ve seen no formal identification at all—I certainly can’t let you remove these children from school grounds. Fortunately, Laura here is Chetwood’s Chief Marshal. Perhaps you’d be good enough to take charge of the observation requirements, Laura? I’m sure the commander has a great deal to be getting on with.”

“Of course,” said Laura, expressionless. Walden thought she caught a flicker of appreciation in her eyes.

Walden went over to the huddle of teenagers. They all stared up at her. They looked extremely pathetic. She adjusted her expression from very scary deputy head to just Dr Walden, you know her. Somewhere to do a formal observation—somewhere magically secure, self-contained, and separate from the rest of the school, but with enough beds for all the exhausted children to get a decent night’s sleep—

There was only really one place in Chetwood’s grounds that qualified.

Walden wasn’t free of responsibility yet. When was she ever? “Come on, you lot,” she said. “Up you get. Sleepover in the Director of Magic’s flat.”

Aneeta was awake, still curled on the couch with her phone. She looked miserable and exhausted. When she heard them come in, she leapt up. “Nikki!” she shrieked, and flung herself at her friend.