In this Percy Jackson mini adventure first published in The Demigod Files, the goddess Persephone summons Percy, Thalia, and Nico to the Underworld to retrieve Hades's powerful sword before it falls into the wrong hands. Easier said than done in a realm full of daimons, ghosts, and monsters. Not to mention Iapetos—brother of the powerful Titan lord, Kronos. Will the demigods manage to find and return the sword before it's too late? Includes an excerpt...

"THE LIGHTNING THIEF: Zeus's master lightning bolt has been stolen and Percy Jackson is the prime suspect. He and his friends have ten days to find and return it and bring peace to a warring Mount Olympus. To succeed, Percy has come to terms with the father who abandoned him, solve the riddle of the Oracle that warns of betrayal by a friend, and unravel a treachery more powerful than the gods themselves. THE LOST HERO: Jason, Piper, and Leo find themselves...

Twelve-year-old Percy Jackson learns he is a demigod, the son of a mortal woman and Poseidon, god of the sea. His mother sends him to a summer camp for demigods where he and his new friends set out on a quest to prevent a war between the gods.