Wolf couldn’t possibly sit down, so he paced around the reception area. What would he say if . . . ? What would he do if . . . ? But he had no idea what was going to happen.

Wolf heard a sort of electric whooshing sound and turned around. A girl a bit older than him had come through the same door as Wolf. She must have worked out the thing with the code as well. She was dressed a bit like Wolf, in casual clothes from the present day, except when Wolf looked more closely he could see she had sneakers with plastic on them. So not from Wolf’s world, then. Maybe somewhere abroad.

She looked at him. “Hello,” she said.

“Hi,” he said back.

“Do you have any idea what we’re supposed to do?” she said. “I was told to be here by noon. I don’t even know what this is.” She opened her arms as if to take in the whole vast structure. There had to be at least a hundred levels. Over in the far left-hand corner Wolf noticed a glass elevator.

“I have no idea either,” said Wolf. “I think you have to sort of check in with him.” Wolf watched her walk up to the reception desk and saw she was also given a name badge. Eventually there was a crackle and a voice came over a loudspeaker.

“Would Mr. Wolf Reed proceed to level seven. Mr. Wolf Reed to level seven, please.”

Wolf shrugged at the girl and started heading for the elevator.

Then the same metallic voice spoke again.

“Ms. Lucy Dare to level seven please. Ms. Lucy Dare to level seven.”

Lucy hurried after Wolf, and they got in the elevator together.

“Do you know why you’re here?” Lucy asked Wolf, as the glass doors shut.

Wolf pressed the button for level seven.

“I’m looking for my sister,” he said. “A man rang and told me to come here. What about you?”

“My mother,” she said. “She’s been moved to a new clinic. I was told to come here to get the address.”

“Did whoever spoke to you mention anything about a program?”

“No,” said Lucy. “What’s that?”

“I don’t know,” said Wolf. “But I don’t like the sound of it.”

“You may approach,” said the long-haired black guinea pig in the cage on the table at the back of the shed.

Neptune didn’t particularly feel that he needed to be invited. He was already padding toward the table, and then leaping up onto it, wondering what kind of latch was on the guinea pig’s cage. There was no latch that Neptune could not undo. He was unusually gifted in that respect. But as he approached the door of this cage his appetite seemed to diminish. And why did he feel so . . . so . . . ? Why had his legs stopped working?

“Sit,” said the guinea pig.