"A human body starts to decompose four minutes after death. Once the encapsulation of life, it now undergoes its final metamorphosis. 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 is how the Yates boys found what was left of Sally Palmer."