She found the message on a Thursday.
Not the morning — the morning was the same as it always was, the alarm and the toast and Lucas and his shoes and the walk to school, grey again, the sky doing nothing in particular. She'd waved to Gerald at the gate, he'd waved back, the kids had gone in. She'd come home and worked and eaten lunch standing up and worked some more and collected Lucas at three fifteen and done the whole second half of the day in the same half-autopilot she always did.
It was after nine when she saw it.
Lucas was in bed. She was on the couch with the television on and her phone in her hand doing the thing she did most evenings where she scrolled without reading anything, just moving her thumb, filling the quiet. She went through her emails. She went through the news. She opened the school group chat to check if anyone had said anything about the book week thing Grace had mentioned on Tuesday and that was when she saw it sitting there at the bottom of the thread, below Grace's message about the car park and Gerald's permission slip question and Kate's voice note that nobody had listened to.
A number she didn't recognise.
She almost scrolled past it. Her thumb was already moving. But something made her stop — not a sound, not a feeling exactly, just a kind of stillness that came over her the way it sometimes does when your brain has registered something before the rest of you has caught up.
She looked at the number. Area code she didn't know. No name attached.
She read the message.
The children in this group have done something that cannot go unanswered. They know what they did. You will have until the 14th of November to make it right. If you don't, I will. — MM
Jessica read it again.
She sat very still. The television was going — some panel show, people laughing at something — and the sound of it felt suddenly wrong, too bright against the quiet of the house.
She read the message a third time.
The 14th of November.
She opened her calendar. November 14th was three weeks and two days away. A Thursday. It was just a Thursday. It didn't mean anything. She stared at it as though it might tell her something and it didn't.
She went back to the message.
MM. She didn't know anyone called MM. She went through her mental index of school parents, of work contacts, of anyone she'd met in the last year — nobody. The initials sat there on the screen looking back at her, saying nothing.
The children in this group. Lucas. Oliver. Isla. Charlie. Four kids. Her kid.
They know what they did.
She thought about the morning. Jackson Cooper standing alone by the bins, watching the boys walk away. Oliver saying something she hadn't been close enough to hear. Lucas laughing.
She pushed the thought away. That wasn't — kids did that. It was normal kid stuff. It wasn't something.
She screenshotted the message and stared at the screenshot for a moment and then typed underneath it: Has anyone else seen this? Does anyone know who MM is?
She sent it and put the phone face down on the cushion and looked at the ceiling.
She picked it back up.
Grace had already replied. Spam. Has to be. Someone got the wrong chat. Then a second message a few seconds later: Also who even has this number? It's a group chat, not public.
That was the thing, Jessica realised. It wasn't a public number. You had to be in the chat to send to it. She'd set the chat up herself eighteen months ago — just the four of them, added manually. So either someone had shared the link, or—
Gerald: When did this come in? I've only just seen it.
Jessica: Not sure. I found it just now. Could have been earlier today.
Gerald: What is MM.
Kate, three minutes later, which meant she'd been reading back through the thread before responding: I don't know but I'm going to find out. Jess can we talk tomorrow.
Jessica looked at the time. Ten past nine. She should go to bed. She had an early start and she was tired and there was almost certainly a rational explanation for this — a wrong number, a joke, some kind of spam that had somehow found its way into a private chat in a way she didn't understand but which was definitely explainable.
She went upstairs.
She checked on Lucas.
He was asleep, arm off the mattress, duvet halfway down. She stood in the doorway for longer than she needed to and then went to her own room and lay in the dark and looked at the ceiling and thought about nothing in particular for a long time before she slept.
She got to the school gate early the next morning, which was not something she ever did by choice.
Lucas had been slow — slow eating, slow finding his shoes, slow everything — and she'd overcorrected in her head and rushed them both out of the house ten minutes ahead of schedule and now they were standing at the gate in the cold with a small cluster of other early arrivers while the year three teacher unlocked the classroom block.
Lucas immediately found Oliver and that was the end of him as far as social availability went. Jessica stood with her hands in her coat pockets and watched the gate and waited.
Gerald arrived at eight forty-two. She could see him coming from halfway down Whitmore Street, Isla ahead of him, his collar up, that same expression she'd noticed yesterday — the low-level worry that might or might not mean something. He saw her as he came through the gate and she could tell from the slight shift in his face that he'd been thinking about the message the same way she had. Isla peeled off toward the classroom block and Gerald came to stand beside Jessica.
"Did you sleep?" he said.
"Not great. You?"
"Barely." He looked out at the yard, at the kids assembling themselves into their groups and configurations. "I kept trying to figure out how they got in the chat."
"Me too. I set it up, I added everyone. It's not a link you can just find."
"Could one of the kids have got hold of a phone?"
She considered it. "I mean, theoretically. But then whose kid, and why, and what does November 14th mean."
Gerald was quiet for a moment. Lucas and Oliver were playing some kind of game near the fence, Lucas making increasingly large arm movements, Oliver losing it laughing. Normal. Completely normal.
"The bit that bothers me," Gerald said, keeping his voice low even though there was no one close enough to hear, "is they know what they did. "
Jessica didn't say anything.
"Because they're eight," he said. "What have they done? They bicker, they fall out, they're—" He stopped. He looked at where the kids were standing, and she knew they were both thinking about the same thing without saying it, the way parents sometimes communicated in absences, in the pauses around the things they didn't want to name directly.
"It might be nothing to do with that," Jessica said.
"Yeah," said Gerald. He didn't sound convinced. She wasn't either.
Isla waved to him from across the yard and he raised a hand back, and for just a moment his face softened completely out of its worry and she could see exactly how much he loved that kid and it made her chest do something she didn't examine.
"What are you going to do?" he said.
"I was thinking about going to talk to Mr Ben. This morning, if he's got a minute."
Gerald nodded slowly. "That makes sense. The message came through a school chat, he might know — I don't know. Something."
"It felt like the right place to start."
"Do you want me to come?"
She thought about it. "You could. Actually, yeah. Two of us is probably better than one."
The bell rang. Lucas gave her a wave that was half goodbye and half an instruction not to embarrass him and then he was gone through the classroom door with Oliver, Isla had already disappeared inside, and suddenly it was just parents at the gate, the yard emptied in that fast way it always emptied, the whole busy noise of the morning gone like a light switching off.
They walked toward the main office together.
Mr Ben's door was open.
The sign on it said Principal — Mr B. Harland in the kind of laminated lettering that looked like it had been there since the nineties, slightly yellowed at the edges. Through the gap Jessica could see a desk with a lot of paper on it and a motivational poster on the wall behind it that said EVERY DAY IS A CHANCE TO BE BETTER in large blue letters. She knocked on the door frame.
Mr Ben looked up. He was a compact, square-shouldered man in his mid-fifties with reading glasses pushed up on his forehead and the air of someone who was genuinely trying to stay on top of things and occasionally succeeding. He'd been principal at the school for six years, Lucas's whole time there. She'd spoken to him maybe four or five times. He was fine. Competent. Not the kind of man who alarmed you, which she supposed was what you wanted in a principal.
"Mrs Viheart," he said. "Mr Kneckhard. Come in." He gestured to the two chairs across from his desk and they sat. He looked at them over his reading glasses with the particular look of a school principal bracing for any one of a thousand possible conversations. "What can I do for you?"
Jessica showed him her phone. The message, the number, the screenshot. She talked him through when she'd found it, who was in the chat, the fact that the number wasn't saved in anyone's contacts. Mr Ben leaned forward and read it carefully, twice, the way she had. He had a small vertical line between his eyebrows that deepened as he read.
"MM," he said, sitting back.
"Do you know who that is?"
He was quiet for a moment. Not the quiet of someone thinking — more the quiet of someone deciding how much to say. "You said it came through the school group chat. The one you set up for the walking arrangement."
"That's right."
"And you don't know how this number got in there."
"No. I added everyone myself. It's Grace Blair, Gerald—" she nodded sideways — "Kate Summer-Sinclair and me. That's it. This number isn't any of us."
Mr Ben tapped the arm of his chair once, twice. "The initials MM," he said. "I wonder — there is a parent, or guardian rather, of one of the year three students. We have very limited information on file for her. She's never come in for any of our meetings. Phone calls go unanswered during school hours." He paused. "The student's name is Jackson Cooper."
Jessica felt Gerald go still beside her.
"We've been trying to address some social issues within the year three group," Mr Ben continued, choosing his words carefully in the way people chose their words when they were talking about something they had opinions about but were trying to present neutrally. "Jackson has been finding things difficult. I've sent letters home. I've called." He looked at the phone again. "The contact name on file is listed as M. Cooper. We don't have a first name beyond that initial. The children apparently refer to her as—" he paused again — "Mummy Maureen."
The room was very quiet.
"So MM could be her," Jessica said.
"It's possible. I want to be careful about jumping to—"
"Has she ever threatened anyone before?"
"I wouldn't characterise this as—" He stopped. Looked at the message again. Looked at her. "I don't know enough about her to say. She has never communicated with the school in any way that I would describe as threatening. She has, in fact, barely communicated with the school at all."
"Can you call her? Now?"
He picked up his desk phone and dialled. They sat and listened to it ring. It rang seven times and went to a voicemail that simply beeped without a recorded message, no name, no instruction, just the tone. Mr Ben left a brief professional message asking M. Cooper to return his call at her earliest convenience and hung up.
"I can try again later," he said. "I do want to take this seriously. But I also don't want to—"
"What about the police?" Gerald said. It was the first thing he'd said since they'd sat down and his voice came out slightly rougher than he probably intended.
Mr Ben considered this. "That's absolutely your right. I wouldn't discourage you from doing that. I'd simply say that as it stands this is an ambiguous message from an unidentified sender and the police may or may not be able to do very much with it."
"November 14th," Jessica said. "That's three weeks away. That's not very much time to wait and see."
"I understand that." He looked at her steadily. "I'll keep trying to reach her. I'll let you know the moment I make contact. I'd ask that you let me know if anything else comes through on that number."
He said it like a man who was doing his job and doing it properly but who also didn't have the specific tool required for the specific problem sitting in front of him. She recognised it because she felt it herself sometimes — the feeling of reaching for something and finding the shelf empty.
They thanked him and left.
Outside in the corridor Gerald let out a long slow breath.
"So we have a name," he said. "Sort of."
"MM. Mummy Maureen." She said it out loud. It sounded strange. Like something a child would say. "And she's Jackson's mum."
Gerald looked at the floor for a moment. Then: "Jess."
"I know."
"The thing yesterday morning. At the gate."
"I know, Gerald."
They stood there in the corridor with the class sounds coming through the walls around them, twenty different rooms full of children getting on with their morning.
"So what do we do?" he said.
Jessica thought about it. She thought about Kate's message the night before — I'm going to find out — and about Grace's certainty that it was spam, and about Lucas asleep with his arm off the mattress, and about Jackson Cooper watching her son walk away.
"We find out who she is," she said. "Before November 14th."
Gerald nodded. Like he'd expected her to say exactly that and had been waiting to agree with it.
They walked out of the school together into the grey morning and went their separate ways, and behind them in his office Mr Ben dialled M. Cooper's number one more time and listened to it ring and ring and ring.