Callum stood up and stepped into the flickering light of the fire.

“Listen, Arran,” he said. “You’re scaring the little ones.

We know it was tough today. We know you got hurt and you lost Deke and all that. We know why you’re angry, but . . . well, go easy, yeah?”

“Yeah, sorry,” said Arran, and he wiped sweat from his forehead.

Callum stayed standing.

“Can I say something else?”

Arran nodded.

“We mustn’t ever leave here.”

“Didn’t you listen to anything I said?” asked Arran.

“This is our home now,” Callum went on. “It was bad luck today. That’s all. We’ll just have to be more careful, yeah? We’ve made this place safe. We’re learning all the time. We’ve survived this far. Why shouldn’t we carry on? I been on the roof nearly all day, and I can tell you, I seen it out there. It’s not safe, yeah? Not safe at all. . . .”

Almost as if to illustrate Callum’s point, there was a crash and a yell from the street below, followed by a hideous scream.

Josh scuttled over the roof from the crow’s nest and shouted down to them.

“There’s something out there!”

Arran could see the fear in the faces of the smaller kids.

Callum was right. All he had succeeded in doing was to frighten them. He should have been more careful about what he said in the meeting. Should have kept his temper. The kids looked up to him. They expected him to never show any doubt.

But he felt rotten and he couldn’t pretend anymore. He was scared too. He was scared twenty-four hours a day, and he was sick of having to spend all his time feeling tense and fearful, like a wild animal.

And now it had happened. The thing he had feared most. He was wounded. Already he could feel a twitching, scratchy heat clawing at his neck. He put his hand to the bandage. His head was swimming, like he had a bad cold.

It wasn’t the wound that had changed him, though. It was the grown-up back at the pool. The mother. He had looked into her eyes and he had recognized something.

He shook his head. He had imagined it. It couldn’t be.

Someone was shouting.

He shook his head again.

“Arran, what’s going on?” It was Callum. He looked panicked. “Are they attacking us?”

He was surrounded by them, all these kids who depended on him. They needed him to tell them what to do. Even if he was wrong, he had to look like he was in control. His feelings didn’t matter right now.

“No,” he said, standing up. “They’ve never attacked before.”

“But you said they were changing. . . .”

“They can’t change that fast.”

He moved in through the sliding glass doors to the canteen, which was off to one side of the terrace. There was another thud from below. A scraping sound as if something was trying to get in. Would the grown-ups really attack Waitrose?