The lost story / Meg Shaffer.

Once upon a time, two boys went missing in the woods. Six months later, they reappeared, with no explanation for where they'd been or how they'd survived. Fifteen years on, Rafe is a reclusive artist with no memory of what happened during those months, despite the scars he bears. Meanwhile, Jeremy is a famed missing persons investigator. With his uncanny abilities, he is the one person who can help vet tech Emilie Wendell find her long-lost sister, who vanished in the very same forest as Rafe and Jeremy. Jeremy also keeps a secret: the fantastical truth about the magical realm they made home for those six months. And it's there they may find Emilie's sister. Alongside Emilie, Rafe and Jeremy must return to the enchanted world they left behind - for only then can they get back everything and everyone they've lost.