The Emerald Atlas - John Stephens

The first thrilling book in the most exciting children's fantasy series since Harry Potter.
They were taken from their beds one frozen night, when the world was covered in snow. The silhouette of a tall, thin man has haunted Kate ever since.
Ten years on, Kate, Michael and Emma have grown up in a string of miserable orphanages, and all memories of their parents have faded to a blur. Arriving at Cambridge Falls, the children quickly realise there is something different about this place - and Kate feels sure she has seen the dark, crooked house before.
As they explore, they discover an old, empty leather book. The moment they touch it, an ancient magical prophecy is set irrevocably in motion, and the children are thrown into a dangerous alternate reality of dark enchantments and terrifying monsters. Only they can prevent the terrible event that will ruin Cambridge Falls - and stop the world from falling into complete devastation.