In his long lifetime the Magician had experienced wonders. He had come to accept the extraordinary as ordinary, the strange and wonderful as commonplace. Dee had seen the legends of the Arabian Nights come to life, had fought with monsters from Greek and Babylonian myth, had traveled through realms that people believed were lies created by the travelers Marco Polo and Ibn Battutah. He knew that the myths of the Celts and the Romans, the Gauls and the Mongols, the Rus, the Viking and even the Maya, were more than stories-they were based on fact. The gods of Greece and Egypt, the spirits of the American plains, the jungle totems and the Japanese Myo-o had once lived. Now they were remembered as little more than fragments of myths and snatches of legend, but John Dee knew that they had once walked this earth. They were part of an Elder race who had ruled the world for millennia.

One of the greatest of the Elders was Mars… and less than twenty-four hours earlier, Dee had encased him in a tomb of solid bone.

The Magician stepped into a vast but low-ceilinged circular chamber, the floating light painting everything sallow, the color of pale butter, and looked around the chamber. Although he’d known about its location for decades, he’d never had a reason to venture down to face the Sleeping God before, and everything had happened so quickly yesterday that he hadn’t had a chance to examine the sepulchre. He ran his hand down a section of the smooth wall beside the door, the scientist within him recognizing the materials: collagen fiber and calcium phosphate. The walls here were not stone-they were bone. Dee spotted two indentations against the far wall. Between them were two dimpled depressions, and suddenly he knew what he was seeing and realized where he was. He was looking at a set of eyes and a nose. The chamber had not been hollowed from a single piece of bone, as he’d thought-he was inside an enormous skull. Terrifyingly, the skull looked almost human. Dee felt a shiver run down his spine; he’d never encountered them, but he’d heard stories of Shadow-realms inhabited by cannibal giants. Yesterday, the walls had been smooth and polished; today they looked like a candle that had been left too close to a fire. Long-frozen stalactites of bone dripped like sticky toffee from the ceiling; huge bubbles had been caught and frozen as they popped; dribbles and streams of thick liquid curled in ornate patterns.

In the center of the room was a long rectangular raised stone plinth splashed and spattered with globules of what looked like yellow wax. The ancient slab was cracked in two.