For eighty million years, the Tourists have taken Snapshots of Earth, creating living replicas of continents. Life in the Snapshots quickly diverges from the real world, creating a universe where humans and animals from Earth's history fly between Snapshots, exploring, fighting, and sometimes meeting their alternate history selves. In 2014, the Tourists create a Snapshot of North America in a snow-globe shaped artificial universe, linked like pearls on a necklace to other copied times and places. In that timeline, Simon Royale-a.k.a. Simon-2014- is a legendary best-selling author. When he was only seven-years-old, his sister mysteriously vanished. Simon-14's writing-and the power in it-is born from his obsession with discovering what happened to her. But now, cut off from the life he'd known, he may never find out.US-53 isn't really the past. Thanks to the Tourists, it's a mutant off-shoot, the 1950s grown up and sneaky, with sharp elbows. In this version of the timeline, Simon Royale-a.k.a. Simon-53-is just an aspiring author with a trunk full of unpublished novels. Then the two worlds connect. For an ambitious publishing company, it looks like a golden opportunity for Simon-53 to leverage Simon-2014's fame.Can the clashing versions of Simon Royale coexist in the unnaturally linked timelines? Simon-2014's legal battle over the right to his own work and identity are the least of his worries. In the 1953 timeline, his sister is still alive. What made her disappear in one reality but survive in the other? Is something dangerous hidden in his memories or his first novel? As Simon inches closer to the truth, one thing is clear: it's a secret someone is willing to kill to keep.