“But enough of this sulking, Mr. Cooper. It is time for you to speak. I have always known you for a boy who has a good heart. Or have your father’s interests poisoned you?”

And Charlie looks past him, watching the slow movement of the sun across the frost-bound pane, like the fog lamp of a distant ship. In front of it stand the water jug and two filled glasses, alight with its glow.

ф

As the day wears on, Charlie finds it increasingly difficult to take his eyes off the water. It stands four feet from the foot of the bed. The more Charlie stares at it, the more details he sees. The two glasses are filled to precisely the same level. One has a chink in the glass that refracts the light across the water’s surface and adds texture to its shadow. The laws of optics bend the window cross directly behind: at times it is the glasses that appear flat and the window behind that bulges with volume. When Charlie struggles hard enough against his manacles to agitate the whole of the bed, the old floorboards pass on the movement to wall and windowsill and conjure a ripple: trembling water; a speck of dust suspended in the left glass sent dancing until it glues itself to the inner wall and adds its shadow to the pattern. Charlie swallows past his drug-thickened tongue, hunts his mouth for spit, finds Soot sown like grit amongst his gums, and realises he must have been smoking. When he glances over at Renfrew, he catches him, too, eyeing the water with the intensity of longing. The schoolmaster rises abruptly, walks in stiff long strides to the window and lifts one glass up to his eyes.

“The human organism can live without water for four or five days. Longer, perhaps, in our humid climate. And yet, it isn’t dusk yet, and we are both struggling with our fast. Ah, the flesh is weak.” He chuckles softly and replaces the glass in precisely the same position. “A good lesson this.”

When he bends over Charlie to look him in the eye, his breath is sour with his thirst.

“Will you tell me what I need to know, Mr. Cooper? For the good of the realm?”

“No,” says Charlie, his dry lips hurting with the word.

“Then we must continue to suffer, in our modest little way.”

ф

Renfrew leaves him. For a moment Charlie has a vision of him, sitting in his kitchen, downing pint after pint of fresh water. But at once he knows this is not true. Renfrew is a man of his word. It’s what makes him so terrifying.

Soon Charlie can hear the scrape of a spade against stone. The schoolmaster is clearing a path from door to fence. Charlie pictures him working with brisk, efficient movements, a scarf knotted high, unfurling his long, gaunt shadow away from the dipping sun. It will be dark before long.