The Undermire Chronicles-The Council of Bone

Charley Ashe is a normal enough boy, or so he thinks. After he is attacked by a large, black dog, his world is flipped upside down.
With his parents acting weird and odd things happening all around him, Charley is skeptical. So, along with his three best friends, he is determined to find out what exactly is going on. This leads to a meeting with a dubious Sorcerer and a hero from a different time.
When he finally unravels what is going on, and that not only he but his closest friends must travel to Undermire, a world very different from their own. He is tasked with saving Undermire from the Wilting and also from a dark force that is always on the verge of finding him.
What is most chilling of all, though, is the dark prophecy saying that he will become the very thing that he must try to save Undermire from.

'In the land mired in misery and hate,
The one of two will be born who may slay the eldest one.
Descended of ash, he will deal in fate.
To cut away the ancient sickness, Ash will battle Bone.
Can the hero save his light
or be doomed to fall to darkness?'