This book cover image released by Disney Hyperion shows &quot;The House of Hades,&quot; by Rick Riordan. The million-selling children's author is set for next week's release of the fourth book of his &quot;Heroes of Olympus&quot; series. Disney Hyperion, an imprint of Disney Publishing Worldwide, has announced a first printing of 2.5 million copies and the 600-page novel already is in the top 5 on Amazon.com. (AP Photo/Disney Hyperion)