"Greek and Roman demigods from the Prophecy of Seven must work together to seal the Doors of Death--and help Percy and Annabeth escape the Underworld in the process"--

Demigod Percy Jackson, still with no memory, and his new friends from Camp Jupiter, Hazel and Frank, go on a quest to free Death, but their bigger task is to unite the Greek and Roman camps so that the Prophecy of Seven can be fulfilled.

Jason, Piper, and Leo, three students from a school for "bad kids," find themselves at Camp Half-Blood, where they learn that they are demigods and begin a quest to free Hera, who has been imprisoned by Mother Earth herself.

"What if Meg had to become a Greek god? After Hercules proves he's a true hero and regains his godship, all seems right in the world. That is, until Zeus tells Meg that she can't be with Hercules because she's, well, mortal. Luckily, Hera has a solution, offering Meg a chance to prove herself worthy of a spot on Mt. Olympus--as a god. All Meg has to do is complete a mysterious quest. The mission? Oh, just to rescue her ex's current wife from the Underworld....