When Hazel Stanczak was born, an interdimensional rift opened up near her family's home. Early on, her parents realized that if she went too far from home, the rift would become volatile and drop things from other dimensions onto their front lawn. So Hazel has never left her small Pennsylvania town, and the government agents that have studied her and the rift her whole life want to make sure she stays put. That's mostly fine with Hazel, who struggles with anxiety. But on her sixteenth birthday, the rift starts acting up even when she's still nearby, causing chaos and panic. In the confusion, Hazel comes facetoface with a surprise: a second Hazel. Then another. And another. And another. Each one of the Hazels is slightly different, but all obviously and definitively her. Now, Hazel has to step outside her comfort zone and into the world to learn how to stop the rift-but can five versions of one sixteenyearold girl really save the world?