How do you punish an immortal? By making him human. After angering his father Zeus, the god Apollo is cast down from Olympus. Weak and disoriented, he lands in New York City as a regular teenage boy. Now, without his godly powers, the four-thousand-year-old deity must learn to survive in the modern world until he can somehow find a way to regain Zeus’s favor. But Apollo has many enemies—gods, monsters, and mortals who would love to see the former Olympian permanently destroyed. Apollo needs help, and he can think of only one place to go . . . an enclave of modern demigods known as Camp Half-Blood.

Magnus Chase, a once-homeless teen, is a resident of the Hotel Valhalla and one of Odin’s chosen warriors. As the son of Frey, the god of summer, fertility, and health, Magnus isn’t naturally inclined to fighting. But he has strong and steadfast friends, including Hearthstone the elf, Blitzen the dwarf, and Samirah the Valkyrie, and together they have achieved brave deeds, such as defeating Fenris Wolf and battling giants for Thor’s hammer, Mjolnir. Now Magnus faces his most dangerous trial yet. His cousin, Annabeth, recruits her boyfriend, Percy Jackson, to give Magnus some pointers, but will his training be enough?

Who cut off Medusa’s head? Who was raised by a she-bear? Who tamed Pegasus? It takes a demigod to know, and Percy Jackson can fill you in on the all the daring deeds of Perseus, Atalanta, Bellerophon, and the rest of the major Greek heroes. Told in the funny, irreverent style readers have come to expect from Percy, ( I’ve had some bad experiences in my time, but the heroes I’m going to tell you about were the original old school hard luck cases. They boldly screwed up where no one had screwed up before. . .) and enhanced with vibrant artwork by Caldecott Honoree John Rocco, this story collection will become the new must-have classic for Rick Riordan’s legions of devoted fans–and for anyone who needs a hero. So get your flaming spear. Put on your lion skin cape. Polish your shield and make sure you’ve got arrows in your quiver. We’re going back about four thousand years to decapitate monsters, save some kingdoms, shoot a few gods in the butt, raid the Underworld, and steal loot from evil people. Then, for dessert, we’ll die painful tragic deaths. Ready? Sweet. Let’s do this.

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?