“Enthusiasts,” I said. “They all volunteer to work here in their spare time. All obsessed with a particular period, or device. They keep the exhibits in order, just for the joy of it. Express the slightest interest in their particular pride and joy, and they’ll talk your ear off.”

“Now, let me be sure I’ve got this right,” said Molly. “This Time Train you want to use . . . No one’s actually taken it out of the hangar in ages, it’s pretty damned dangerous even when it’s working properly, and the only guarantee we have it’ll work at all is some dedicated amateur technician? Have I missed anything? You are not filling me with confidence here, Eddie.”

By now we’d reached the Time Train, and the sheer size of the thing dwarfed all the other exhibits. The Time Train itself was a big, black, old-fashioned steam engine, gleaming and glistening like the night, with luxurious silver and brass fittings, all of them buffed and polished to a cheery warm glow. Half a dozen luxury Pullman coaches, in the familiar milk chocolate and cream livery, stretched away behind the coal tender. A quick peek through the coaches’ curtained windows revealed a whole other world of seats and fittings whose quality would have shamed the Orient Express in its heyday. The family never did believe in doing things by half. The huge black engine towered over us like a sleeping beast, only waiting to be roused. A tall gangling individual appeared suddenly in the cab and smiled bashfully down at us.

“Oh hello,” he said. “Visitors, how nice. We don’t get many visitors, old Ivor and me. Ivor is the engine, you see.”

“Yes,” I said. “I had a hunch it might be. Molly, allow me to present to you the family’s one and only expert steam train engineer: Tony Drood. Latest in a long line of such enthusiasts, right Tony?”

“Oh yes,” he said, clambering agilely down the gleaming steel ladder on the side of the cab to join us. He had to be in his late fifties, though his hair was still suspiciously jet-black. He wore a set of grubby overalls, and his hands and face were covered with dirty smudges from whatever he’d just been working on. He finally stood before us, smiling and bobbing his head just a bit shyly. “An honour to meet you both, Edwin and Miss Molly. Can’t remember the last time anyone of quality came to see us, eh, Ivor, old thing?”

He reached up and fondly patted the bulging black steel chamber.

“Ivor really is very . . . impressive,” said Molly, and Tony beamed at her as though she’d just taken a thorn out of his paw.

“Impressive he is indeed, Miss Molly, and that is no lie. I have made it my business to see that he is kept spotless, and in perfect working order, ready to go at a moment’s notice.”