I noticed now what I should have noticed before: in the far wall was another metal door. I opened the door. This room beyond was walled in concrete, not wood. Along one wall was a workbench, scrupulously clean.

Nothing in any of the drawers. Nothing in the cupboards. Everything was stripped clean, washed down. But there were taps here, and porcelain sinks, and gas burners. And in the far wall, yet another metal door, which I had to bend to enter. How confident Bror had been that I would not dare open it when he encouraged me to visit his dogs. How certain he had been of my limits.

It was warm in this little room. The air smelled of burnt feathers and lighter fluid. Something worse too. Some memory of the air in town after the bomb, as Vee and I tried to make our way home.

In the far corner was a pit dug into the mud floor, filled with sand. I stepped forward. The heat intensified.

I thought at first that Bror had been burning banknotes. There were scraps here, charred at the edges: thin papery sheets, baled together with wire. I reached out, then realized the edges of the bale were smoldering. The charcoal he had used glowed dully. I kicked the bail out of the pit and on to the floor. There was writing on the edge: printed lettering in red and blue.

I returned to the kennel room. The dogs were sleeping peacefully now, snoring quietly to themselves. I took their metal dish, filled it with water, returned to the fire pit. I doused the bale on the floor, then went to refill the dish.

The fire-damaged paper was fragile, especially now that it was wet, but I managed to free the outer sheet. It was dark in here. Too dark to read the tiny print. I walked past the sleeping dogs, stood blinking in the harsh summer light.

It was part of a thick paper sack, heavily charred. I squinted at the print. Phosphate-based fertilizer. Product of the People’s Republic of China. The basic ingredient of so many terrorist bombs.

I called Tvist, asked him to come as soon as he could. Then I set about finding tools so I could split the chains and free the dogs.

He came alone in his gray gull-wing Tesla. The dogs were milling about, walking large arcs around the farmhouse, patrolling the perimeter, staring out into the gathering twilight. They stopped as Tvist approached, turned to face him, silent statues, their sinews sprung with steel. Still the storm had not broken.

“Another couple of hours and the evidence would have been gone.” I handed Tvist the fire-damaged paper. “Here’s your fertilizer-bomb factory.”

“It’s rarely that simple, Cal.” He took out a flashlight, held the paper up to the light.