I followed the sound, off to my right. The trees were moving now in the wind, their branches swaying, and with it came the sound of pine needles scratching the roof. I raised the rifle and looked through the scope, sweeping the gun from left to right in an effort to see beyond the treeline.

And that was when I spotted him.

A distant figure, in the forest.

He was heading away from me, his movements jerky and unstable, as if the ground were uneven, and as he took a furtive glance over his shoulder he almost lost his footing entirely.

I broke into a sprint.

It took me ten seconds to get to the treeline, and as soon as I passed the first row of pines the sound seemed to deaden completely. It was like going beneath the surface of a lake. In front of me, to the sides, everywhere I looked, massive trees went on for ever – spruce, yew, aspens, their trunks as high as cathedrals – and while the temperature wasn’t as raw beneath the canopy, the ground was like concrete. Every step jarred my muscles and joints, the weeks of inactivity weighing on me now.

But I kept going, pushing on, looking up, way ahead of me, as Mills drifted in and out of sight. The trees were rammed together so tightly there was no defined path, every possible trail packed with leaves, debris from branches and exposed roots. The limbs dipped and bowed, swiping at me as I passed, and on the ground – pockmarked with pine needles and bird tracks – there was still a thin blanket of snow.

I heard the snap of twigs up ahead, the crunch of leaves, but couldn’t see him at first. Then I passed through a narrow gap between two huge pines and spotted him up ahead, maybe only eighty feet away now, a dense fog gathering above him.

Was he really tiring already?

I picked up the pace, pushing down my own exhaustion, concentrating on my own footsteps, where they fell, trying to gain more ground and more distance on him.

And then I looked up to check where he was.

He was gone.

I stopped, watching the spaces ahead of me. When he didn’t appear, I moved towards the tree closest to me, the bark gummy with sap, and peered past it. There was no sign of him. I rounded that tree and went to the next, quietly, but still couldn’t see him.

Where the hell was he?

Instantly, the size of the forest seemed to pull into focus and I felt a flutter of panic. I’d come a quarter of a mile, maybe even more, but it was nearly impossible to be sure: I couldn’t see the treeline any more, let alone the clearing or the house. I wasn’t even certain if I was looking in the right direction.