He looked underneath the wheels but couldn’t see anything. Then he pushed up his spectacles.

“I think there is something in here,” he said. “Between the wheel arch and the carriage floor.”

“May I see?” said Patrick. “I have very small fingers that are really very useful.”

Mr. McCredie passed the carriage over to Patrick, but he didn’t have much more luck. Whatever it was, it was just out of reach.

“Hang on,” said Carmen suddenly. She rummaged in her big handbag and for once came up trumps with a stray set of tweezers. “Let me see.”

They handed it over somewhat dubiously as she carefully pulled something out that was tucked just behind the wheel arch.

It was a very old, faded photograph, soft around the edges, black and white, folded up.

Mr. McCredie started suddenly and gripped the side of the desk.

“Are you all right?” said Carmen.

“I think . . .” he said weakly. “I think I’d better go and sit down . . .”

Carmen—and Patrick—followed him through the stacks to his little fireplace.

“Ooh, I like this very much!” said Patrick approvingly.

“Patrick,” said Carmen. “I wouldn’t normally ask you, but could you go back and see your mum and dad for a minute?”

Patrick opened his mouth to say a lot of very important things he needed to tell Carmen about his mum and dad, but when he saw the look on her face, he promptly shut it again and went off without a word. Carmen had grabbed a glass of wine as she went and handed it to the old man, who sat heavily in his chair and then slowly, and with trembling hands, unfolded the little photograph.