"One boy. One deadly prophecy. One heart-stopping adventure. This is how the world will end: on 22 December, an electromagnetic pulse will blast through the atmosphere. Technology will fail. Civilization will fall apart. The key to survival lies in a secret Mayan book, protected by Josh and an ancient society. But someone has altered time. To put it back on track, Josh must unravel history itself and face the dangers of a dark, parallel reality. The fourth book in the internationally bestselling sequence."