There have always been breaches—tears between realities—and they've always been a threat to humanity. Most people are blind to them. But Hallie's eyes are opening. Now that she's going to school at the Protectorate, she's learning there's more to life than fun and games. 

The truth is, she's just become part of Earth's only shield against the monsters on the other side of those breaches. Before, she didn't think she was anything special. Now, yanked from her relatively normal life, she's realizes that she doesn't have a choice. 

When the emergency alarm sounds, calling everyone in the school to arms, even the young and inexperienced are needed. As one of the warp weavers—people capable of closing the breaches and stopping the monsters—Hallie must now work to save lives. And she must do it in the most complicated situation she's ever experienced. Because there are sea serpents in the Thames, and Hallie has to close the doors that are letting them in. 

The problem is, they're underwater, and they're hungry. 

Now everyone is relying on her, and Hallie must find a way to do her job—with a brand new partner—before it's too late. Because if she fails she'll die, along with everyone who's depending on her.