He was keeping a lookout for Arran’s scav party. They needed Arran back. Everyone was on edge since Small Sam had been taken. Arran would calm everyone down, sort things out. Stop the little ones from being scared.

Callum never went scavenging. He had convinced the others that he was more use to them on the roof. In fact, he hadn’t been out of Waitrose, except to come up here, for nearly a year. There was an invisible rope attaching him to it. In his mind he wandered the streets below, like a character moving around a game, but in real life he never wanted to go out there again. Waitrose was safe. He had everything he needed here. He was happy. Almost happier than he had been before the disaster.

The one thing he longed for, though, was peace and quiet. To be alone, really alone. That would be bliss. To just sit there, in all the space of the shop, without it being full of other kids. Sitting here in the crow’s nest was as good as it got.

He put his binoculars to his eyes and scanned the Holloway Road.

“Come on, Arran, we need you. . . .”

They were limping along. Ollie and Achilleus were walking ahead of Arran and Freak, who were both silent, lost in private thoughts. Ollie knew well enough not to push it. If the other two didn’t want to talk about what had gone down, then he wasn’t going to try to make them. Freak had lost his best friend, and Arran had been badly bitten. Ollie hadn’t expected him to take it so badly, though. Arran was tough. Hated showing any weakness in front of anyone else. Something had happened to him back at the pool. He had the look of someone who had stared at something nasty. Stared for too long.

Arran’s skin had been punctured. There would be a big danger of infection. The grown-ups were filthy and riddled with germs and disease. Luckily, Arran hadn’t been in the water, but the mother who had attacked him had looked pretty foul.

Why had Arran frozen like that? All the fight went out of him. One minute he was cracking skulls with his club, and the next he was just standing there, in a dream. Had he lost his nerve?

Arran had to know that nobody would blame him for what had happened to Deke. It had been Freak’s stupid idea to go into the pool. How could they have prepared for the ambush? It wasn’t like grown-ups—usually they were stupid and slow and confused. Not much different from the pack of dogs the gang had dealt with earlier. This bunch had acted together. Organized. A team.

How many of the adults had they killed? he wondered. He knew for sure he had hit seven of them, but it didn’t mean that each shot was a killing shot. When they’d bundled out through the reception area he’d seen two of his targets lying still on the floor. He must have fired thirty pellets, maybe more. It had been too dangerous to try to collect them afterward. He had a pile back at the camp, but it was a lot to lose in one day. At this rate it would be sooner rather than later that he ran out altogether. He’d have to find some more, or start collecting pebbles.