"This book left me breathless!" —R. L. Stine, #1 New York Times bestselling author of Goosebumps and Fear Street

"Move over, Stranger Things." —Melissa de la Cruz, #1 New York Times bestselling author of the Descendants series

New York Times bestselling authors Ally Condie and Brendan Reichs team up to co-author this thrilling first book in a darkly suspenseful middle grade series.

Everyone in Timbers knows Still Cove is off-limits, with its creepy Beast sightings and equally terrifying legends. But when a bullying incident sends twelve-year-old Nico Holland over a cliff and into Still Cove's icy waters, friends Tyler and Emma—and even Opal Walsh, who usually runs with the popular kids—rush to his rescue . . . and discover a mysterious island hiding in the murky, swirling mists below.

Though the island appears uninhabited, the kids can't shake a feeling that something about it is definitely not right. Their suspicions grow when they stumble upon an abandoned houseboat filled with all sorts of curiosities: odd-looking weapons, unnerving portraits, maps to unknown places, and a glass jar containing something completely unidentifiable. And in its lowest depths churns a dark, deep secret.

As the group delves deeper into this mysterious new clubhouse, their lives begin to intertwine in weird and dangerous ways. For something ancient has awakened . . . and it can detect not only their wishes and dreams, but also their darkest, most terrible imaginings. Do they have what it takes to face the shadowy secrets lurking within their own hearts?

Told from alternating points of view, this pulse-racing tale from bestselling duo Ally Condie and Brendan Reichs is the start of a high-stakes, thrilling series about friendship and believing in yourself—and each other.