He rocked back and forth, on the verge of laughter, trying to keep his mind blank, waiting for the panic to subside. And eventually, it did -- to be replaced by one simple, perfectly coherent thought: I don't want to be here.

What he'd done to himself was insane -- and it had to be undone, as swiftly and painlessly as possible. How could he have ever imagined reaching any other conclusion?

Then he began to remember the details of his preparations. He'd anticipated feeling this way. He'd planned for it. However bad he felt, it was all part of the expected progression of responses. Panic. Regret. Analysis. Acceptance.

Two out of four; so far, so good.

Paul uncovered his eyes, and looked around the room. Away from a few dazzling patches of direct sunshine, everything glowed softly in the diffuse light: the matte white brick walls, the imitation (imitation) mahogany furniture; even the posters -- Bosch, Dali, Ernst, and Giger -- looked harmless, domesticated. Wherever he turned his gaze (if nowhere else), the simulation was utterly convincing; the spotlight of his attention made it so. Hypothetical light rays were being traced backward from individual rod and cone cells on his simulated retinas, and projected out into the virtual environment to determine exactly what needed to be computed: a lot of detail near the center of his vision, much less toward the periphery. Objects out of sight didn't 'vanish' entirely, if they influenced the ambient light, but Paul knew that the calculations would rarely be pursued beyond the crudest first-order approximations: Bosch's Garden of Earthly Delights reduced to an average reflectance value, a single gray rectangle -- because once his back was turned, any more detail would have been wasted.