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 4,000-year-old deity must learn to survive in the modern world until he can somehow find a way to regain Zeus' favor. But Apollo has many enemies - gods, monsters, and mortals who would love to see the former Olympian permanently destroyed.

As the son of Hades, Nico di Angelo has been through so much, from the premature deaths of his mother and sister, to being outed against his will, to losing his friend Jason during the trials of Apollo. But there is a ray of sunshine in his life—literally: his boyfriend, Will Solace, the son of Apollo. Together the two demigods can overcome any obstacle or foe. At least, that's been the case so far . . . Now Nico is being plagued by a voice calling out to him from Tartarus, the lowest part of the Underworld.

Ana Dakkar is a freshman at Harding-Pencroft Academy, a five-year high school that graduates the best marine scientists, naval warriors, navigators, and underwater explorers in the world. Ana's parents died while on a scientific expedition two years ago, and the only family's she's got left is her older brother, Dev, also a student at HP. Ana's freshman year culminates with the class' weekend trial at sea, the details of which have been kept secret. She only hopes she has what it'll take to succeed.

What would happen if you discovered that your family was one of the most powerful in human history? What if you were told that the source of the family's power was hidden around the world, in the form of 39 Clues? What if you were given a choice - take a million dollars and walk away...or get the first Clue? If you're Amy and Dan Cahill, you take the Clue - and begin a very dangerous race.

Magnus Chase has always been a troubled kid. Since his mother's mysterious death, he's lived alone on the streets of Boston, surviving by his wits, keeping one step ahead of the police and the truant officers. One day, he's tracked down by an uncle he barely knows - a man his mother claimed was dangerous. Uncle Randolph tells him an impossible secret: Magnus is the son of a Norse god. The Viking myths are true. The gods of Asgard are preparing for war. Trolls, giants and worse monsters are stirring for doomsday.