"The Greek and Roman demigods must simultaneously prevent the earth mother, Gaea, from waking and stop war from breaking out at Camp Half-Blood"-- Provided by publisher.

Leaving the safety of the demigod training ground, a disgraced Apollo embarks on a quest across North America to find a dangerous ancient-world Oracle while navigating the challenges of the evil Triumvirate.

Will the Greek god Apollo, cast down to Earth in the pathetic mortal form of a teenager named Lester Papadopoulos, finally regain his place on Mount Olympus? Lester's demigod friends at Camp Jupiter just helped him survive attacks from bloodthirsty ghouls, an evil Roman king and his army of the undead, and the lethal emperors Caligula and Commodus. Now the former god and his demigod master Meg must follow a prophecy uncovered by Ella the harpy. Lester's...

"In his penultimate adventure, a devastated but determined Apollo travels to Camp Jupiter, where he must learn what it is to be a hero, or die trying"--

At the conclusion of The Mark of Athena, Annabeth and Percy tumble into a pit leading stragith 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 Door 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...

While the Olympians struggle to contain the rampaging monster Typhon, Kronos begins his advance on New York City, where Mount Olympus stands virtually unguarded. Now it's up to Percy Jackson and an army of young demigods to stop the Lord of Time.

In the house of Helios, god of the sun and mightiest of the Titans, a daughter is born. But Circe is a strange child -- not powerful, like her father, nor viciously alluring like her mother. Turning to the world of mortals for companionship, she discovers that she does possess power -- the power of witchcraft, which can transform rivals into monsters and menace the gods themselves. Threatened, Zeus banishes her to a deserted island, where she hones...

"Seventeen-year-old Pierce Oliviera knew by accepting the love of John Hayden, she'd be forced to live forever in the Underworld. But now her happiness and safety are threatened because the Furies have discovered that John has broken one of their strictest rules, and the only way to fix the balance is for someone to die"--

Emily is contending with great changes, including diminished powers, but goes to London to rescue Agent B and others from the CRU, where she makes horrible discoveries about the agency's history.

"Pegasus and Emily investigate a series of incidents back on Earth, and discover that the CRU has been cloning Olympians"--