This incursion—a critical incursion, with a demon in control—was shaping up to be bigger than the one in Arizona. But then, Old Faithful was bigger than anything anyone had ever dared summon for mere research purposes. The archdemon that had been going for Will must have been a secondary scavenger. Walden saw a few others about the same size as she made her way through School House, as well as plenty of smaller imps feeding on the household electronics and delighting in the unexpected treat. There was nothing larger. Anything big enough to present a challenge to Old Faithful was also smart enough not to pick a fight with it.

In a peculiar backwards way, Old Faithful was an asset to Chetwood. They had far fewer serious demon problems than a school full of underage magicians should, because the one higher demon they did have was so huge and so terrifying that it had scared off all the competition. And, in turn, Old Faithful was so big that the everyday half-trained magic of schoolchildren was barely enough to tempt it. It lay quiescent, uninterested, lazy: a great white shark swimming among the little fish, unwilling to waste effort on anything less than a plump and juicy seal.

Unfortunately, a pair of talented sixth formers fit the demonic definition of ‘juicy seal’ almost perfectly.

Walden, under the barrier of her glowing white shield, tried to move quickly. The physical geography of School House, which she knew well, was of limited help. She made it back to the kitchen, but could not find the staircase which she knew ought to be there. She only had two hours. “Think, Saffy,” she muttered aloud when she felt herself starting to panic.

Silence. And in that silence, another sound: a series of treble yelps and whimpers, and a regular swish and crack.

It took a moment for Walden to understand that she was hearing the sound of a child being beaten with a cane. Horrific. But she went towards the noise, because it was what she had. She found herself walking through a wall which, come to think of it, must have been put up when the kitchen was last remodelled, and into a room that no longer existed: a wood-panelled teacher’s office out of a history book, rather like Walden’s own. Next to the desk, the phantom figure of some sadistic Victorian schoolmaster was caning a boy whose age Walden could only place as ‘too young for secondary school’—perhaps eight or nine. Chetwood had been offering a complete education for young magicians since the fourteenth century. At one point, it had accepted pupils as young as five.

She murmured a variation on the standard banishment and sent it towards the apparition with a sharp gesture. The schoolmaster disintegrated. Hard to guess what it had been. An imp latching onto a memory of strong emotion was more likely than a true ghost.