12-year-old Amber Herold ran away from the orphanage 2 years ago. She now lives in a clock tower in 1932 England. She steals from shops on a daily basis, struggling to survive. But when a blue box appears in a dark alleyway, her life takes an unexpected turn.

Aine Sterling, daughter of Nyx, closed the door from the inside of Tartarus for Percy Jackson and Annabeth chase. But once trapped in the Underworld, how will she survive? Can she make it through her mother's House of Night and get out of Tartarus?

Nax Wylder suffered his whole life for nothing. Now that he has a chance to prove he isn't worthless, he isn't going to let himself die just yet.

Cordy was only a mortal girl, minding her own business in the world when they came. Ugly, horrible monsters they were, and she could see every one of them. When a few people her age showed up and told her it was all real, she thought they were crazy, too. But the more she heard the more she believed. Maybe the Greek myths were real after all. Maybe she would fit in somewhere. But being the only mortal at Camp Half-Blood was a hard job, even if she could see through the "mist". And when she realises who she really is inside, her world may come crashing down.