This book is the Land of Stories: World's Collide by Chris Colfer. The genre of this book is fantasy because magic is involved and there are different worlds made up from the author's imagination.

The book is about a girl called Alex and her twin sister, Conner. Alex had been secretly cursed to follow the witchs' orders by the witches. Alex, who had magic in her blood was taken from the real world to the fairy tale world. After recruiting literary heroes, Conner has to face up against witches, literary villains, and.... His sister. Conner's army fought well and were on the verge of winning. All was well until the witches gave Alex orders to destroy the world. Defeating the witches would be a feat in itself, but getting Alex out of the curse would be nearly impossible. Conner knew this was for all the marbles and he needed to brainstorm his plan, quick.

I liked this book and the adventure in it.  --Reviewed by Anirudh V.