Harry's Backup Plan

Delaney stood by the Stone Platform for a long time, holding the glass tube.

His thumb pressed against the wall of the tube, feeling the outline of that small patch of dried residue through the transparent material, as though he were confirming by touch whether its texture had changed at all after being sealed.

The detector had already been switched off. Once its screen went dark, the only sources of light in the room were the illumination orb on Harry's shoulder and the flashlight in Ron's hand. Their beams met and parted along the curved edge of the ceiling, dividing the Stone Platform into alternating sections of light and shadow.

Hermione crouched in the corner, carefully shining her flashlight over the pile of pottery shards without touching them.

The fragments were stacked atop one another. The uppermost pieces retained a semicircular curve, as though they had once been part of some vessel.

She studied them for a while before speaking. "These fragments should have come from the same source. Look—the angles of the fractures at the joins are consistent. It looks like the same object was smashed and then piled up here."

She turned toward the spiral markings on the southern wall, rose to her feet, and moved closer. "The spacing is the same too. The width of each ring is almost evenly spaced, and the grooves are all equally deep. They couldn't have been carved at random. It looks more like something used to record cycles—seasonal changes, perhaps, or some repeating event."

Delaney slipped the glass tube into his inner pocket, walked over to the markings, and crouched down. He shone his flashlight at an angle across the wall. "The spiral ends here."

His fingertips rested at the outermost edge of the spiral. "The line breaks off here. There