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.
