On a cold autumn night, twelve-year-old Remi Cobb makes a startling discovery—a mysterious object floating on the pond in her backyard. With no idea where it came from, or how it got there, Remi is compelled to unravel its secrets. Her quest for answers takes her on a perilous journey across realities, where she finds a crumbling world—and the dark forces behind its ruin. Here she learns the truth about her connection with the strange object, and of those that will stop at nothing to destroy them both. But even if she can find a way to survive, can she find a way home?