"Them?" Yale said with apprehension.

"They were easy to make. They were interesting. I don't know how many we had, but quite a few."

"my God."

"There might be one still in the playroom," I said. "The old train sets are there."

Yale looked at me balefully. "How many of your family saw these devices?" he asked.

"Everyone."

"Who made them?"

"I did, Gervase did, and Ferdinand. Thomas did. I don't remember who else."

"But your whole family knows how to make a simple time-switch?"

"Yes, I should think so."

"And why," he said, "haven't you mentioned this before?"

I sighed and twisted the wired clock hand round in my fingers. "Because," I said, "for starters I didn't think of it until after I'd left here the other day. After we'd been digging out the black powder and so on, and I'd been looking back to the past. I didn't want you to find this. I wanted you to find something sophisticated, that no one in the family could have thought up."

"Hm," he said, seeming to accept it. "How many people outside your family knew about these clocks?"

"Several did, I suppose, but it was such a long time ago. No one would remember, would they?"

"They might." Yale turned to Smith. "This toy, is this really what set off the bomb?"

Smith nodded. "It sounds just right. Wire in a detonator where the Pembroke children had a torch bulb…" He spread his hands. "it wouldn't need more current than that."

Not surprisingly, they decided to take a look in the playroom. They picked their way cautiously across the ankle-twisting rubble and headed for the passage which was comparatively clear by this time. The playroom, when we reached it, was shadowy inside, with the windows boarded up. Light of sorts seeped in through the door, but it took a few minutes for eyes to acclimatise, during which Yale bumped into the bicycles, knocking them over. I helped him pick them up. He wanted to know whose they were, and I told him about Peter and Robin.

He made no especial comment but watched while I went over to the shelves and began peering into boxes. I hadn't been in the room at all since the twins had gone, and their own playthings had overlaid those outgrown and abandoned by their elder brothers and sisters so that most of what I was looking at was unfamiliar and seemed to belong to strangers. It took several minutes to locate the box I thought I wanted, and to pick it off the shelves and put it on the table.

Someone, Coochie I dared say, had packed the trains away for good after Gervase and Ferdinand had left and I'd been busy with school and horses. At one time, the tracks had run permanently round half the room, but Peter and Robin had been television-watchers more than the rest of us, and hadn't dragged them out again. I opened the box and found the old treasures undisturbed, looking more battered than I'd thought, with rust on the much-used wheels.

I lifted out a couple of engines and some coaches, then followed them with a tunnel, a signal box with green and red bulbs and a brown plastic railway station adorned with empty bulb-holders among the advertisement stickers. I suppose to any adult, his childhood's rediscovered toys look smaller, deader, less appealing than he remembers. The trains were dusty and sad, relics ready for the skip outside, melancholic. The little lights had long gone out. I took everything out of the box, but there were no clocks.

"Sorry," I said. "They could be in anything, really. If they're here."

Smith began looking into any box whose contents weren't easily identifiable by the picture on top. Yale, with a no-hope expression, followed suit. I packed the trains back into oblivion with regret.

"Well, just look here," Smith said suddenly. "Gold mine."

He had produced from a jumble of Lego constructions a bright new- looking clock with a Mickey Mouse face in unfaded technicolour. Mickey's hands in fat white gloves were the hands of the clock. To the minute hand was fixed a coil of white plastic-covered wire. A second white coil was stuck to the scarlet clock casing, its bared end jutting out over noon. When Smith held it all up, the white coils stretched out and down like curling streamers.

I looked at it blankly.

"I've never seen that one before," I said. "We didn't make them decorative. Ours were…" I sought for the word "… utilitarian."

Smith picked away among the Lego. "Can't find a battery," he reported. "Nor a torch bulb, for that matter." A pause. "Wait a minute…" He rattled around and, finally, triumphantly produced a red and white Lego tower with a bulb-holder lodged inside near the top. "A lighthouse, wouldn't you say?" he asked, standing it upright. "Neat."

"Someone made this for your twin brothers," Yale said. "Are you sure you never saw it?"

I shook my head. "I didn't live here then, only visited. The twins had a short attention span, anyway. They tired of new toys pretty quickly. Always wanted to get on with the next thing."

"I'll find out who made it," Yale said. "Can you sort out a box to put it in? I'll give you a receipt, of course."

Smith found him an empty Lego box and into it they packed the bright co-star of an act that had brought half the house down. There was room in the box for the lighthouse, so they took that, too. Yale solemnly wrote a receipt on a page of his notebook and gave it to me, and with him carrying the box we went out into the daylight, blinking as our eyes adjusted after the gloom.

As we walked back in the general direction of the trestle table, Smith said, "We've put all the clothes we've found on a table in the garage. I'm afraid they're mostly torn and unwearable, but you might want to see. All the personal things we've salvaged are in a cardboard carton. Do you want to take those today, or wait until we're finished?"

"Look now, take later," I said.

Smith half smiled. "They're in that box under the table."

I squatted down beside the brown cardboard carton and opened the top flaps. Inside there was quite a good collection of dusty bits and pieces, more than I would have imagined. I picked out one of Malcolm's precious brushes and ran my finger over the gold and silver chased backing. The dust came off and the metal shone in the sunlight. He would be pleased, I thought.

"We've found five of those," Smith observed. "Two are badly dented, the others look all right."

"There were eight," I said. "In his dressing-room."

He shrugged. "We might find more."

I turned over a few things in the box. Mostly they were uninteresting, like a bottle of aspirins from the bathroom. At the bottom, I came across one or two things of my own – an empty sponge bag and the tape recorder.

I lifted the recorder out, straightened up and put it on the table. Pressed the start button. Absence of results.

"It was just a chance you might want it," Smith said philosophically. "It doesn't work as it is, but you might want to get it mended."

"Probably cheaper to buy a new one," I said.

I pressed the rewind and fast-forward buttons pointlessly, and then the eject button, which worked. The plastic lid staggered open, revealing a tape within. I had to think for a minute which tape it was and then remembered it was only the one from my answering machine; nothing interesting. I shut the lid and put the recorder back in the box under the table.

"If you find my camera, now that would be good news," I said, straightening again. Yale had lost interest and was preparing to leave.

"Was it yours?" said Mr Smith. "It's in the skip, I'm afraid. Badly smashed."

"Oh well…"

"Were you insured?"

I shook my head. "Never thought of it."

Smith made sympathetic gestures and went back to the rubble. The superintendent said I should telephone him the following morning without fail. He ran his thumb and finger down his moustache and asked me if I now knew who had bombed the house.