We entered the small room, the candlelight breathing over the veiled windows, the shelves of books, a desk littered, like the sitting room, with documents heaped and strewn about. The flame’s unsteady respiration seemed to plunge the place into an element like water. The objects seemed to undulate and swim in and out of view before us.

Tick-tick. Tick-tick.

I stepped forward cautiously, Quentin at my back. It was here, whatever it was—here, or just nearby. The sound seemed to vibrate up out of the very heart of the chamber. I could not help but tense, the flame flickering as my grip on the candle tightened, as the sound came again.

Tick-tick.

“Where is it?” I whispered hoarsely.

“Neville …”

“Where is it?”

He inclined his head towards the books on the wall to my left. “That case there,” he said reluctantly.

In two strides, I was at the bookcase he indicated, a tall case of some dark wood, its shelves lined with musty leather volumes. Uncertainly, my hand went out to touch the bindings. Quentin continued to protest behind me.

“Neville, let us turn back, let us consider, there is more to say, much more you do not know …”

A book—-a heavy black book with no lettering on its ribbed spine—shifted inward beneath my fingers. There was the sound of a latch giving way. The entire case seemed to snap free of the wall. With a whining screak, it swung towards me on a hidden hinge.

I pulled the case open as if it were a door to reveal the narrow staircase winding into the blackness below.

Tick-tick. Tick-tick.

Now, at last, as if drawn from the house’s timbers, drawn from the air around us, from my own brain, the sound resolved itself upon a single centre, a single source. It ascended in its unceasing, funereal tempo from the dark at the base of the stairs.

Tick-tick.

I started down to meet it.

“No, Neville!”

As I descended, step by slow step, the damp wooden boards groaning thickly beneath my soles, Quentin’s gibbered warnings spiralled into a frantic skirl.

“You do not blow, you have not understood, you must believe me, I have thought on these things for weeks, I have tried to comprehend …”

My own shadow dodged and capered in bizarre shapes on the dripping stone walls around me. My heart was thudding in my chest and there was a thickness in my throat that nearly made me gag.

As my foot touched the bottom step, I felt a clammy draught twine round my legs. The candle flame swelled and, in the broadening glow, I saw before me a door of rotted wood hung in hammered iron bands.

Tick-tick. Tick-tick.

The sound was coming from behind the door. Nervously gnawing my lips, I willed my hand to reach out for the ring that secured it.