“Which can only strengthen the case against Clifton Bradshaw,” Charlotte said. “Who else would be able to spend so much time alone in that room, certain they would be undisturbed? And it was he himself who told us he kept the only key on his person at all times. It seems likely the child’s death was related directly to Mary Bradshaw’s death—an unwitting victim of Bradshaw’s grief and rage”—she looked at the design—“or some demonic ritual to restore her health?”

“We should consider Liston,” Emily suggested. “He was grieving too, and if he attempted to emulate his father—then anything could be possible.”

“But he was just a child at the time,” Anne said, “barely twelve years old.”

“There are plenty of that age who have lived a lifetime by then,” Emily said. “Let us consider Old Bess, then. There is something very . . . unsettling about that woman. I believe she thought she was telling me secrets today, though I could make neither head nor tail of anything she said, rhymes and songs, biblical verses, all tangled up with all manner of nonsense. Molly was keen to quiet her down before she could say more, as if she had been told to do so. I had thought it was a show of Bradshaw’s decency that he’d kept her on and not sent her to an asylum, but perhaps he is afraid that even as weak-minded as she is, she might yet reveal his secrets.”

Anne watched as Emily slotted another stone into place. The strange and mysterious intentions of the creator were gradually becoming whole, if utterly unintelligible.

“It is also useful to note that another fire was never lit after these marks were made,” Emily said. “Otherwise they would be obscured by soot. So we can assume that, as we suspected, the remains were placed in the wall, and this . . . whatever it is . . . was completed after Mrs. Bradshaw died and Clifton closed up that part of the house. That makes the mostly likely opportunity for the event itself to be that summer and harvest period up at Top Withens.”

It was Charlotte who slotted home the last piece, and though she couldn’t be certain, Anne wouldn’t have been at all surprised if her sister hadn’t kept that stone aside especially to gain that dubious honour. In any case, once the sisters looked at the whole picture carved into the rocks, a sense of deep unease swept through them in a single shuddering wave, and Keeper, who had been sleeping peacefully under the table, rose up all at once and howled a long plaintive cry that struck the sisters dumb.

“Shush, boy,” Emily said, seeking to pull the dog into a hug, but he shook her off, scratching to get out at the door where Flossy was already barking, desperate to be free.

“Something has set the dogs off,” Charlotte said anxiously.