Cackle's Academy woke slowly as the autumn days faded into winter. Pale sunlight streamed through the streaky glass of the castle's five-hundred-year-old windows and cast uneven shadows on the floor, and in dormitories and corridors, the girls began to stir, pulling on uniforms, splashing water on their faces, and applying forbidden lip gloss and mascara that they hoped would escape notice. The smells of semolina porridge and burnt toast filtered up through the stairwell from the kitchen, creating no anticipation among those who would shortly be eating them. Breakfast was the least dreaded of the twenty-one meals per week served at Cackle's, but still did little to excite girls who started their mornings at home with sugary cereal at best, or crisps and chocolate at worst.

Somewhere between the dormitories and the dungeon, Miss Hardbroom, who did not eat breakfast and who had fortified herself with a double shot of Wide-Awake potion just after midnight, was passing the early hours of the day by brewing up an experiment in her laboratory. When it was empty of young witches' noise and disorder, the lab was one of the few places where Constance felt truly calm. She enjoyed the methodical task of laying out her tools and ingredients in a sort of magical mise en place, and found comfort in the rituals of measuring and stirring and adding each element at exactly the right moment. The cold did not bother her much, and even if it had, the small fire under her cauldron was enough to take the edge off the chill. She could happily have stayed all day, tinkering with different combinations, and often did when no other duties called her.

She was just tipping a beaker of pale pink liquid over her new creation, gripping it with a pair of tongs for safety's sake, when a voice spoke from the door.

"Constance, I need you to come with me."

"One minute, Headmistress," Constance said, still pouring the beaker's contents into the seething heart of the cauldron with a steady hand. "If I don't finish incorporating the oleander extract now, the whole thing will be spoilt."

"Right now," Miss Cackle said, and the strange tightness in her tone was enough to make Constance look up and set the beaker aside at once.

"What is it?"

"I think I had better show you instead of telling you." Miss Cackle glanced at the cauldron. "Can you leave it?"

"Not like this." Constance strode to the door, pulling off her protective gear as she went, and leant out into the corridor. "Griselda Blackwood, come here. No, not you too, Fenella Feverfew. Despite what you may believe, you and Griselda are not permanently attached at the hip."

Griselda, who had been heading to breakfast early in hopes of getting a piece of toast before it went soggy, came into the laboratory looking displeased but resigned. "Yes, Miss Hardbroom?"

"I need you to take this cauldron off the fire and when the potion has cooled enough, pour it down the disposal drain for dangerous substances. It will be extremely toxic at this stage, so wear gloves and goggles, and wash your hands when you've finished. If you're too late for breakfast, you may go down to the kitchen and get something from Mrs Tapioca before your first lesson. Do you understand?"

Griselda nodded, and Constance glared at her.

"Perhaps you didn't hear what I said, Griselda. If you had, surely you would have answered properly, would you not?"

"Yes, Miss Hardbroom. Sorry, Miss Hardbroom."

"Very good. Carry on." Following her own advice, Constance scrubbed her hands under icy water in the lab sink, and then departed in Miss Cackle's wake, leaving Griselda to sit hunched up on a stool, looking like a short, blonde mad scientist in her elbow-length gauntlets and leather goggles, and wait for the potion to stop bubbling.

"Headmistress, at least tell me where we're going," Constance hissed as they headed down the main stairs and toward the castle's great front doors. She prided herself on not being easily frightened, but Miss Cackle's silence, combined with the speed at which she was walking and the grim look on her normally kindly face, made Constance feel like throwing up the breakfast she hadn't eaten. She lengthened her stride, worried that in a moment she would have to break into an undignified trot to keep up. "Headmistress, please."

"To the forest," said Miss Cackle. "Imogen is waiting for us there."

"But why? What is it?"

Instead of answering, Miss Cackle herded her through the door and, after looking around to make sure no one was watching or listening, pulled her aside into the deep shadows of the gatehouse.

"She's found a body."

"A body?" Suddenly dizzy, Constance put a hand against the nearest wall so as not to fall over. The solid smoothness of its timeworn stone steadied her a little, and she went on. "Do you mean a dead body?"

"Yes." Miss Cackle saw her deputy sinking and seemed to realise what was wrong. "It isn't one of our girls, Constance."

"Oh, thank heavens." Constance breathed out a long sigh of relief, trying to push away the image that had leapt fully formed into her head: Mildred Hubble, creeping out in the night and finally stumbling into some disaster from which there could be no recovery, killed by her own carelessness before Constance had a chance to teach her better sense. What would she have said to the girl's parents?

"Thank heavens," she said again, weakly. "But...if it isn't one of the girls, then who is it?"

"I've no idea." Amelia prodded her onward and they started toward the main gate. "Imogen was out for an early-morning run and found the woman—it is a woman, I know that much—near to the castle. She came straight away to notify me, and then went back to watch over the body until we could get there." They were crossing the lawn that led up to the forest's edge now, their shoes leaving dark footprints in the frost-white grass. "It isn't far now. Imogen said it was just beyond the tree line."

"There she is," said Constance, spotting a bright flash of colour between the tree trunks and tangled shrubbery and knowing it could only be one of the garish tracksuits that Miss Drill favoured. An instant later, Miss Drill herself came jogging toward them with a face full of frantic worry.

"What on earth took so long? I've been waiting ages. Anyone might have come along."

"Thank you for standing guard, Imogen," Miss Cackle said. "Can you show her to us, please?"

"Of course." Miss Drill ran an agitated hand through the short, fair cap of her hair. "She's just over here. I haven't touched her at all. The police don't want you to. I've seen it on television." She looked from Constance to Miss Cackle, searching for confirmation and not finding it. "We are going to phone the police, aren't we?"

"We'll see," Miss Cackle said.

"What do you mean, we'll see? Someone has died! Why wouldn't we tell the police?"

"Because, Miss Drill," Constance said, "if she is a witch, then there are different authorities to notify. But we won't know if she is a witch or not until—"

At that moment, they pushed through some long, flexible branches and came upon a tiny clearing, and in it, the motionless shape of a woman lying huddled at the base of an ancient oak, with her back turned on the three intruders whose conversation was disturbing her quiet rest.