They held their breath as Mr. McCredie replaced the plug, which had been round and brown and made of Bakelite, and, amazingly, the little train took off, light on at its front, trundling around the track. Not only this, but the signal lights worked too, lifting and lowering as the train drew near.

They stood watching it, completely entranced.

“We need smoke pellets,” said Mr. McCredie, who looked nearly tearful at his childhood toy come back to life.

“How . . . ? Is that how they make smoke?” Carmen crouched. There were even tiny plastic figurines in the passenger carriages: women in little hats reading newspapers, men in suits with trilbies and broad shoulders. There was something slightly sinister in the thought that they had been up there, trapped in their carriages for forty years, stuck in an eternal waiting room. But of course that was fanciful nonsense.

“Of course.”

“You know, I could get cheap lights too, from Poundworld,” mused Carmen. “And put them in the trees for Christmas. And some cotton wool for more snow.”

“Poundland.” Mr. McCredie frowned. “What on earth is that?”

“I’m taking you,” said Carmen. Then she reconsidered. “No. You might have a heart attack. But just give me a bit of petty cash and trust me.”

“I can’t believe we have . . . a ‘window display.’”

“How . . . ?” said Carmen. “How on earth are you a shopkeeper?”

“I prefer ‘custodian,’” said Mr. McCredie, but he was too distracted by the little train.

Carmen went back into the main house and through the rest of the old Christmas decorations, discarding the crumbling and irretrievable, but there was a surprising amount of good-quality little gold-colored candlesticks, a beautiful ceramic nativity set, some brass angels, and, loveliest and strangest of all, a dollhouse that looked not unlike Sofia’s house, with its steps up with a perfect little rug and beds and the dearest patterned armchairs, blankets, and curtains, but instead of little people inside there were little dressed toy mice, perfect in every way, with fur and whiskers and little bright beady eyes, wearing waistcoats and spectacles, aprons and bustles. Carmen had to suppress something in her that would very much have wanted it for herself.

Then followed a rather jolly afternoon of splurging on artificial snow and tiny strands of lights at the happy, busy Poundworld. As Carmen worked on both windows—trains on one side, dollhouse on the other—more and more people stopped by to see what they were doing, and several popped in and bought books.