When he woke, he couldn’t remember if he’d ever woken before. He didn’t know where he was anymore than a newborn child knows its whereabouts the moment it’s born. He was ages old, and yet he couldn’t remember. He heard a whisper of wind, whistling and moaning. No rustling leaves. No flowing water. What was he? He knew he was not human. He was something greater than human. His eyelids fluttered.

The light blinded him, but he forced his eyes open. His heart fell. For a being without memories, he nonetheless knew absolutely, terribly, that this was not the way the world was supposed to be. Words he hadn’t remembered two seconds ago tumbled into his mind: desert, wasteland, barren, dead, destroyed, nothing—stop! His chest was heaving, his hands clenched at his sides. The earth he stood on was dry and cracked. Overhead, boiling black clouds obscured something he knew was called the sun. Ash rained from above, a slow pall over the funeral of the earth. Beneath its blanket, nothing stirred. Nothing was green. …

There were no grass, no trees—he remembered these things, but they were not here. No animals. Poking out of the ash here and there were signs of an expired civilization: the wing of a crashed aircraft here, the skeleton of a satellite tower there. Metal scrap and other perplexing human creations were scattered over the landscape, decaying and lifeless. Bits of metal shaped and molded, their purpose long forgotten. He felt a pulsing energy at thecenter of his chest and looked down to see a radiant quartz embedded over his heart.

Welcome to awakening, a voice boomed in his mind. You have been woken to fulfill your purpose. You must rewind the clock of time to restore Planet Earth to its former abundance. Once this is accomplished, you must alter the course of history to prevent it from re-destroying itself. The quartz has been charging for millennia, drawing power from the ultimate source of creation. In order to accomplish your mission and reverse time, all the energy accumulated within its crystalline structure will be spent.

When you wake again, it will be empty. The demigod—for, suddenly, he knew that’s what he was—squared his shoulders. The crystal began to vibrate in his chest, increasing in intensity until colors and shapes melted away before a glaring light. A high-pitched screeching filled his entire body, growing, growing, until— He lost consciousness. When he woke, he moved his hand and grass feathered beneath his touch. An infinity of sounds washed over him: bees buzzing, birds singing, wind passing through leafy tree branches.

The sky was blue. He tried to stand, and a pain stabbed him in the chest. Gasping, he looked down and saw that the quartz in his chest had shattered. Only a small shard lay on the grass beside him. The rest was nowhere to be seen. He inspected the shard. Feeling clumsy, he struggled to fit it back into the cavity in his chest. The moment the shard clicked into place, the world around him convulsed. The sky streaked with ecstatic new colors. The birds flying above him were flying upside-down. Not only that—their wingtip feathers were connected, one bird to the next, so their flying was like a great wave undulating through the air. That was all he had time to see before a flood of light struck him, and the quartz’s voice resonated in his mind: Welcome back. You have rewound time itself.

Now your true work will begin. He wasn’t just hearing the voice—he was seeing it too. Every word sent frissons of light dancing across his vision. Each one had a unique shape, so that he could have interpreted what the crystal said even if no sound reached his ears.

You are Earth’s Timekeeper, the crystal said. I am your master, your superior in the chain of command. Your next task is to recover the other shards of the quartz, which were lost when you rewound time. Once the quartz is whole again, you will have the remaining instructions to complete your mission and seal the fate of this planet.