Like the Infinity Ring and Spirit Animal series--among others from Scholastic--this series has its own interactive, online material. You can visit the official website HERE, where you can create an account (with parent permission) to play the online game related to the book, read the blog and forums related to the story, and see videos.
In the book, main character Alex is searching for something--anything--to save his mother's life. She is certain the Egyptian Book of the Dead can help, but using it also unleashes Death Walkers. When his mom and the Lost Spells disappear, can Alex find her?