again the thing had taken possession of him, convulsing his being.
It came always strongest after a period of strange half-delicious insomnia, during which his mind left him and wandered through the world outside the walls. These periods came often, and lasted sometimes as long as a week. Every night, then, leaving his body tossing, hot, on the narrow bunk in the steel cell, his mind, leaping the walls, flitted from place to place in the wide open world. Dawn saw him always haggard after one of these nights of semi-freedom, and within him the impulse would be crouching, stealthy, waiting to trap him to action. He watched against it incessantly, but a huge irritation vibrated along his nerves.
The whole atmosphere about him, anyhow, now held a suppressed excitement. He had felt it at first as an indefinable thing, a vague restlessness. Then he had become conscious of a subtle change in the routine about him. After several days of close observation, he had been able to place this.
