I recommend 'The Land of Stories' By Chris Colfer.
It is an exciting, falling through the rabbit hole type of book about twins Alex and Connor who fall into a world where fairy tale characters are very real. The novelty very quickly wears off when the threat of being eaten by the witch from Hansel and Gretel or the Big Bad Wolf become a reality.
They must search for items to perform a 'Wishing Spell' to wish for a safe return home but the items are not just almost impossible to source they are also being tracked down by the Evil Queen from Snow White! Who will get to the items first? Will the twins get home?