On the eleventh night, sleep stopped being possible.
It wasn't the room. It was the heat in his bones — the same heat that had come with the injection, which had faded after the first night like water off stone. This time it came back without warning, climbing from the leg-bones upward along the spine, branching into the shoulder blades. Not a fever. Something more deliberate. Like someone drawing a lit wire along the inside of each bone, slowly, section by section.
He made no sound. He had learned early that sound drew attention and attention cost things he wasn't yet ready to spend.
The pain itself wasn't the problem. The problem was what the heat was doing while it burned.
His bones were changing.
Not breaking — something slower and more precise, like the realignment of iron grain as it cools from the forge. He made a fist with his left hand, opened it. The knuckle joints produced a sound he hadn't heard from himself before — not the usual dry crack of a joint stretching, but something denser, duller. Metal on metal.
He turned onto his side and faced the wall and went through it methodically.
He didn't know what had been in the injection. He knew his body was responding to some kind of energy by rebuilding, and that rebuilding required material. The food he'd eaten in the past weeks wasn't enough to sustain his baseline weight. Yet the change continued. Which meant the energy itself was the material, or the material was coming from somewhere else.
He thought about the air.
The air in the Tower's lower floors was wrong in a way he hadn't been able to name — something beneath the damp and the mould, something that moved at the back of the throat like spores, like the exhalation of something old and half-rotted. He had taken it for bad air. Underground stench. He reconsidered.
What that air was to ordinary bodies — a slow drain, a sickness — might be something different to him now.
He reached under the edge of his pillow and retrieved a piece of bread he had saved from breakfast, hard as leather, and chewed it slowly. While he ate he tried something new: he turned his attention inward. Down through the skin and the muscle, into the bone, into the place where the heat was working.
Weight.
A dense and settled weight, like iron stock quenched in water — cold at the surface, still burning at the core. He followed it deeper. At the base of it he found something that didn't belong to ordinary flesh. Dark. Compressed. Solid as char.
He looked at it for a long time.
He didn't know what to call it. No one had told him anything. But it was his — not something the mages had put in him, not the injection. His body had made it.
The heat was gone by dawn.
He flexed his hand. The knuckle-sound was heavier than last night.
Good.