The fourth exciting entry in Rick Riordan's best-selling Heroes of Olympus series is now a graphic novel!
At the conclusion of The Mark of Athena, Annabeth and Percy tumble into a pit leading straight to the Underworld. The other five demigods have to put aside their grief and follow Percy's instructions to find the mortal side of the Doors of Death. If they can fight their way through the Gaea's forces, and Percy and Annabeth can survive the House of Hades, then the Seven will be able to seal the Doors from both sides and prevent the giants from raising Gaea. But, Leo wonders, if the Doors are sealed, how will Percy and Annabeth be able to escape?
They have no choice. If the demigods don't succeed, Gaea's armies will never die. They have no time. In about a month, the Romans will march on Camp Half-Blood. The stakes are higher than ever in this adventure that dives into the depths of Tartarus.

Rick Riordan, dubbed "storyteller of the gods" by Publishers Weekly, is the author of five New York Times #1 best-selling series, including Percy Jackson and the Olympians, which brings Greek mythology to life for contemporary readers. His most recent novels are The Sun and the Star: A Nico di Angelo Adventure, cowritten with Mark Oshiro, and Percy Jackson and the Olympians: The Chalice of the Gods. The goal of his imprint, Rick Riordan Presents, is to publish highly entertaining books by authors from underrepresented cultures and backgrounds, to allow them to tell their own stories inspired by the mythology, folklore, and culture of their heritage. Follow Rick's news on RickRiordan.com.
Robert Venditti is a New York Times best-selling author whose characters and concepts have been adapted to film, television, and video games. He has written the monthly comic book series "Green Lantern,” “Superman '78," and "Justice League" for DC Comics, "X-O Manowar" and "Wrath of the Eternal Warrior" for Valiant Entertainment, and the children's novel series Miles Taylor and the Golden Cape. He has also adapted Rick Riordan's Percy Jackson and Heroes of Olympus graphic novels. He lives in Atlanta, Georgia.
Orpheus Collar is a New York Times best-selling graphic novelist who adapted Rick Riordan's Kane Chronicles trilogy and Heroes of Olympus series. He also contributed artwork to Rick's Percy Jackson and the Olympians graphic novels. Orpheus lives in Los Angeles, California. Learn more at Orpheusartist.com.