I think because I'd heard such mixed reviews of this book I went in with low expectations which I was a little miffed with because the premise sounded so interesting. So, going in expecting it to be mediocre, I ended up utterly loving this book. The first half of the book is a gripping mystery, I'm terrified for these kids, the world is just so ominous, so dark and then somewhere halfway it turns into a sort of fantasy adventure which I really enjoyed! I read this book in a weekend and enjoyed every bit of it. It doesn't take itself too seriously, just an honest great time. Also, I read this when the temperatures were their lowest here and that just added to the feel, I felt I was also trapped in the island with them. I would love to read a prequel to this, I want more of this world - more backstory and world-building of this strange place.