“Mink, maybe? Pine marten?”

I said, “Or human.” It wasn’t the trap in the attic I had thought of, the second I saw what was left of that robin. It was Emma and Jack bouncing out into the garden to play, early one morning, and finding this, all among the grass and the dew. From that hide, someone would have had a perfect view. “Those kill for the sake of it, all the time.”

*

By twenty to six, we were working our way through the playroom area and the light outside the kitchen windows was starting to cool towards evening. I said to Richie, “Can you finish up here?”

He glanced up, didn’t ask. “No probs.”

“I’ll be back in fifteen minutes. Be ready to head back to HQ.” I stood up—my knees jolted and cracked, I was getting too old for this—and left him crouching there, rummaging through picture books and plastic tubs of crayons, surrounded by the blood spatter that Larry and his team had no more use for. As I left my foot knocked over some kind of blue fluffy animal, which let out a high-pitched giggle and started to sing. Its thin, sweet, inhuman chant followed me down the hall and out the door.

As the day started to ebb, the estate was coming to life. The media had packed up and gone home, taking their helicopter with them, but in the house where we had talked to Fiona Rafferty a clutch of little boys were ricocheting about, swinging off the scaffolding and pretending to shove each other out of high windows, dancing black silhouettes against the burning sky. At the end of the road a huddle of teenagers were slouching on the wall around a weed-grown garden, not even pretending not to be smoking or drinking or staring at me. Somewhere someone was roaring furious circles on a big bike with no muffler; farther away, rap was pumping relentlessly. Birds dived in and out of empty window-holes, and by the roadside something scuttled in a heap of bricks and barbed wire, setting off a tiny avalanche of dust.

The back entrance of the estate was two great stone gateposts, opening onto a sweep of swaying long grass that had grown up thick in the gap where the gate should have been. The grass whispered soothingly and clamped tight around my ankles, tugging me back, as I moved down the gentle slope towards the sand dunes.

The search team was at the tide line, picking through seaweed and the bubbling holes where winkles were buried. They straightened up, one by one, when they saw me coming. I said, “Any luck?”

They showed me their haul of evidence bags, like cold children straggling home with their finds at the end of a long day on some grotesque scavenger hunt. Cigarette butts, cider cans, used condoms, broken earphones, ripped T-shirts, food packets, old shoes: every empty house had had something to offer, every empty house had been claimed and colonized by someone—kids looking for places to dare each other, couples looking for privacy or for thrills, teenagers looking for something to wreck, creatures looking for somewhere to breed and grow, mice, rats, birds, weeds, tiny busy insects. Nature doesn’t let anything go empty, doesn’t let anything go to waste. The second the builders and developers and estate agents had moved out, other things had started moving in.