The alternating dimension thing was a really funny idea, didn't expect something like this in this series. All in all the book is a nice book, but I must admit I am not exactly sure if I like the use of Skulduggery's use of Vile and Valkerie's use of Darquess just as a mere tool. Maybe there is a point when that backfires, we'll see hopefully. The tapping thing to break the control over their bodies.. Well not the first surprise here. The attempt of the mirror being (now with a real consciousness) is another thing I never anticipated. Can't await the next book.