The Chemistry of Death

A human body starts to decompose four minutes after death. Once the encapsulation of life, it now undergoes its final metamorphoses. It begins to digest itself. Cells dissolve from the inside out. Tissue turns to liquid, then to gas. No longer animate, the body becomes an immovable feast for other organisms. Bacteria first, then insects. Flies. Eggs are laid, then hatch. The larvae feed on the nutrient-rich broth, and then migrate. They leave the body in orderly fashion, following each other in a neat procession that always heads south. South-east or south-west sometimes, but never north. No-one knows why.

By now the body ' s muscle protein has broken down, producing a potent chemical brew. Lethal to vegetation, it kills the grass as the larvae crawl through it, forming an umbilical of death that extends back the way they came. In the right conditions ' dry and hot, say, without rain ' it can extend for yards, a wavering brown conga-line of fat yellow grubs. It ' s a curious sight, and for the curious what could be more natural than to follow this phenomenon back to its source Which was how the Yates boys found what was left of Sally Palmer.

Neil and Sam came across the maggot trail on the edge of Farnham Wood, where it borders the marsh. It was the second week of July, and already the unnatural summer seemed to have been going on for ever. The heat seemed eternal, leaching the colour from the trees and baking the ground to the hardness of bone. The boys were on their way to Willow Hole, a reed pond that passed as the local swimming pool. They were meeting friends there, and would spend the Sunday afternoon bombing into the tepid green water from an overhanging tree. At least, so they thought.

I see them as bored and listless, drugged by the heat and impatient with each other. Neil, at eleven three years older than his brother, would be walking slightly ahead of Sam to demonstrate his impatience. There ' s a stick in his hand, with which he whips the stalks and branches he passes. Sam trudges along behind, sniffing from time to time. Not from a summer cold, but from the hay fever that also reddens his eyes. A mild antihistamine would help him, but at this stage he doesn ' t know that. He always sniffs during summer. Always the shadow to his bigger brother, he walks with his head down, which is why he and not his brother notices the maggot trail.

He stops and examines it before shouting Neil back. Neil is reluctant, but Sam has obviously found something. He tries to act unimpressed, but the undulating line of maggots intrigues him just as much as it does his brother. The two of them crouch over the grubs, pushing dark hair out of similar faces and wrinkling their noses at the ammoniac smell. And though neither could later remember whose idea it was to see where they were coming from, I imagine it to be Neil ' s. Having walked past the maggots himself, he would be keen to assert his authority once more. So it ' s Neil who sets off first, heading towards the yellowed tufts of marsh grass from which the larvae are flowing, and leaving Sam to follow.