The hallway is long, with maybe a dozen doors on either side of it. Above us the rafters are open in places, exposing shards of blackening sky. More rain is on its way, by the looks of things. My feet tread in something mushy and I look down to see we’re walking on water-logged and rotting carpet, threadbare in places. Beneath, I can see the wooden floorboards are black, and they creak as we walk; an alarm system to thwart our hopes of a surprise attack.

My nerves are frayed, my legs are shaking so hard I can barely stand up, and I feel like I might faint at any moment, but I keep following Liam, sheltering behind his back, terrified that at any moment someone might leap out at us.

Liam opens the first door we reach, and I draw a breath of surprise at the sight of the forest right in front of us. We’re in the nursery that we saw from outside. The exterior wall is completely missing. The rocking horse sits forlornly at the edge of what looks like a cliff, staring out over the grounds. We’re eye-level with the branches. I glance around; the fire must have burned through the floor above, and the attic, too, but oddly enough, the nursery itself is almost untouched. Besides the rocking horse, there’s a chair and a small bed in the corner of the room, complete with the decomposing remains of a mattress.

Liam touches my sleeve and we leave the nursery and keep walking down the hallway, our footsteps silenced by the disintegrating carpet which stinks of fusty mildew. I breathe through my mouth as we keep going, checking every room we pass for signs of occupancy, my fraught nerves ratcheting up with every door handle that Liam tries, until I think I might have to turn tail and run. We find nothing, until we reach the final door.

Liam throws it open and freezes on the threshold. I peer past him and spot a makeshift campsite in the corner of the room; there’s a sleeping bag, a stove, pots and pans and other items, but no occupant in sight. Someone is staying here! But who? And why?

Liam steps into the room, crossing quickly to the sleeping bag. He kneels down and places his hand on the bag and then on the pan sitting over the little camp stove. ‘It’s still warm,’ he says.

He must have been here not long ago. We either only just missed him or – I spin around in fright – he’s still here, somewhere in the castle.

Panicked, I turn back to Liam. ‘We should go, before he comes back.’