C.M. Chidgey 2015

Lucy’s twin sister is missing with no trace, after being orphaned at the age of five Lizzie is the only person she has left. Despite people telling Lucy that her sister is gone she refuses to accept it claiming that she just knows she is alive. Little does she know that Lizzie has quite literally disappeared from the face of the Earth. They both end up in a place where armoured knights riding horses, living in castles and enemy witches are all too real rather than just a story in a book. Saving Lizzie is just the beginning though when she discovers things that maybe she was better of not knowing and her sister is just one of the people she wants to protect.
This is a standalone book and does not end on a cliffhanger.