“The aging thing,” Alex murmured. “In the blood. Slowing down then speeding up . . . living such a long time. Do you think it’s going to happen with me?”

“All I can tell you is, your grandad told me one time that ’e reckoned you’d be okay, Alex. ’E worried about it a lot when you was little, but then your body seemed to sort itself out. Maybe the effects were more potent when you were smaller. Your grandad told me ’e reckoned that the stuff was dormant in you. But if you’re asking me ’ow long you’ve got, well, I mean: nobody knows that, son, do they? You, me, everybody else, we’re all sittin’ in different seats in the same boat.”

They smiled at each other in sympathy.

“And Zia too, now,” Alex said after a moment. “She’ll start aging. Or will she? What will happen to her, with the flower gone, and her father—Harry, has there been any sign of her? Do you think—”

“Nothing,” Harry said, shaking his head. “Disappeared. So,” he went on, clearing his throat. “What do you reckon, Alex? Still want me to do it?”

“I don’t know,” Alex said, suddenly filled with uncertainty. “What do you think?”

“Oh.” Harry leaned back, raised both palms. “Can’t ’elp you there, son. Your decision now.”

Alex watched his grandfather, walking slowly back toward them, bent painfully over his stick, the dog carefully taking its time not to rush him.

There must be a way to help him, Alex thought. Make it better. Turn it back. He knew, if he studied hard enough, if he devoted himself to it, threw himself deep into it, he could find the way, find the words, shape some power. Keep them all safe. And, like that, Alex decided what he was going to do. Then he looked at his grandfather smiling at him and he changed his mind back again.

Alex nodded. “I’m sure.” He took out the old tin toy robot and handed it to Harry. “Take it. Do it. Get rid of it.”

“Righto,” Harry said quietly, and slipped the toy into his bag.

The chips arrived just as the old man sat down. “Oh, those smell good. Can I have one?” he said to Alex.

“Many as you like.”

“Excellent.” The old man took a chip, then used it to point at Alex. He narrowed his eyes. “You know, you look very like my son. What’s your name?”

“Alex,” Alex said.

“Oh, that’s his name! Pleased to meet you. Good name, that.”

They shook hands and chatted and watched the river running in the sunlight. Then it was somehow time to go. Alex had to get back for his mum’s birthday lunch in a fancy restaurant. Meanwhile, his grandfather and Harry had a train to catch. They parted at a street corner, Harry promising to be in touch soon.