The Spirit Tree by Jacqueline Kirk
Price: Free! 27440 words.
Published on May 10, 2011. .
The Spirit Tree cleanses the souls of the newly dead but an evil soul has tainted it and its Guardians, twisting them into something evil.
When Michael's mother becomes a restless spirit, he and his friend James are determined to heal the Tree any way they can! With the help of Billy Blin, a Guardian who escaped the taint, they battle their way to the Tree even when the forest itself fights them!