Awful thoughts came into his head. What if there had been an attack while he was gone? What if everyone was dead?

He ran over to the shutter. It hadn’t been wound down all the way. Again, a grown-up wouldn’t fit through. But he was Small Sam.

He wormed his way under on his belly and stood up. Slowly he walked farther into the shop, fearful of what he might find.

It all looked the same as ever—except that it was deserted.

“Hello?”

His voice sounded feeble and tiny.

He walked deeper inside.

Somebody was in an armchair. In the area at the back, where they had cleared a space and moved in some furniture. Just sitting there. Doing nothing. He wasn’t dead, though. He blinked.

It was Callum.

“Hello?” said Sam, walking closer. “Are you all right?”

Callum nodded slowly, watchful. “How did you get in?” was all he asked. No surprise or joy at seeing Sam back from the dead.

“The barriers weren’t properly shut.”

“I must have not closed them right when they left.”

“What do you mean?” said Sam. “When who left?”

Callum told Sam everything that had happened. Sam slumped down on a sofa, exhausted.

“They can’t have gone,” he said.

“Well, they have. All of them.”

“Except you.”

“Except me.”

“Why didn’t you go with them?”

Callum shrugged. “I like it here.”

“Didn’t you hear me, though?” said Sam. “When I was trying to get in? I rang the bell.”

“I didn’t know it was you, did I? How could I? I thought it was one of them, a grown-up.”

“It was me,” said Sam, and he started to cry. He was so tired. All he wanted to do was lie down on the sofa and go to sleep, but Callum was looking at him in an odd way. Sam was so confused. He wasn’t sure he trusted Callum. Wasn’t even sure that he was telling the truth. Had a raggedy boy really turned up and led everyone away?

“My sister Ella,” he said quietly. “I promised to look after her, and now she’s gone.”

“They didn’t leave that long ago,” said Callum. “You could catch up with them easy.”

“I’d have to go back out there.”

“Yeah.” Callum nodded his head slowly, watching Sam with glittering black eyes.

Sam stood up. “Is there a bicycle pump here?” he said.

Arran’s head was spinning. Walking in the hot sun was boiling his already feverish brain. He felt faint and found breathing difficult. He was trying hard not to show it, but every now and then he would sway and stumble sideways across the road. He took another sip of water. His hundredth since they’d left, it seemed like. At this rate he’d finish his supply before they even got to Camden.

The truth was, he felt awful, and he knew it was serious. Germs had got in through his broken skin and they were breeding in his blood.