“The central nervous system is nature’s Sistine Chapel, but we have to bear in mind that the world our senses present to us—this office, my lab, our awareness of time—is a ramshackle construct which our brains have devised to let us get on with the job of maintaining ourselves and reproducing our species. What we see is a highly conventionalised picture, a simple tourist guide to a very strange city. We need to dismantle this ramshackle construct in order to grasp what’s really going on. The visual space we occupy doesn’t actually coincide with the external world. Shadows are far deeper than they seem to us; the brain softens out the sharp contrasts so that we can analyse them more clearly—otherwise the world would be a mass of zebra stripes …

“Consciousness is the central nervous system’s brave gamble that it exists, an artefact that allows it to make its way around the internal and external environments. In fact, we’re beginning to think that time itself is a primitive psychological structure that we’ve inherited from the distant past, along with the appendix and the little toe. Yet we’re totally trapped by this archaic structure with its minutes and hours trailing after each other like a procession of the blind. Once we get hold of a more advanced notion of time—let’s say, time perceived as simultaneity—we reach the threshold of a far larger mental universe …

“Why do the dying think they’re floating through tunnels? Under extreme pressure, the various centres in the brain which organise a coherent view of the world begin to break down. The brain scans its collapsing field of vision and constructs out of the last few rings of cells what it desperately hopes is an escape tunnel. Right to the end the brain is trying at all costs to rationalise reality—whether it’s starved of input or flooded with sensory data, it builds artificial structures that try to make sense of the world. Out of this come not only near-death experiences but our visions of heaven and hell.”

Everyone had been intrigued, but the BBC declined to buy the series.

“Dr. Sutherland,” the head of science programmes had commented, “your description of the dying brain rather resembles the BBC…”

*   *   *

“Dick, my watch has stopped.”

“Let me see. No, it’s 3:45.”

“It must be later than that…”

I stared at the motionless second hand and tried to work the winder. My fingers felt as cool and sensitive as a jeweller’s, but I had the sudden notion they belonged to someone else. The second hand moved again, then halted for a further indefinite movement. A deep ruby light filled the garden, as if the sun had begun to overheat. I leaned forward, almost falling from the chair, and peered at the vivid cyanide blue of the sky.