Reckless, depressed, impulsive and sixteen, Harrow Lane is going to an island that shouldn't exist to look for answers about the death of her father—the father who accidentally cursed her shortly after she was born. Things immediately go very wrong—beginning with the sinking of the boat that brought them to the island and an ominous chuckle from something that shouldn't be there—and keep getting worse in ways they couldn't possibly imagine.

Harrow and friends came without being invited and whatever lives there doesn't like visitors. With no way to reach the outside world and no understanding of the rules of the island, Harrow and her friends are in mortal danger, and knowing who can and can't be trusted is a thing they left back on shore. Matters are only complicated by Harrow's emotions—she's given her biggest feelings human faces and personalities and does her best to keep them locked away in a seedy motel she built in her mind. But emotions are sneaky, and she's having to face them at the worst possible time.

It's creating sort of an "Inside Out in hell" situation as they fight for survival against a creature that seems to be made entirely of terror and who very well might spell the end of the world.