Is it Alive? Annaliese doesn't understand why her mysterious father drops her off at her Uncle Ed's house, or why, for that matter, he enrolls her into a local school in the town. With the promise he'll be back, he was gone, and Annaliese knew he wouldn't be back for a long time. Riley Carson sees monsters--demons, to be exact. The kind that if you see one and so much as try to hurt it it'll snatch your throat and rip it out. She has ever since she was young, and always thought it was just a thing she was born with. So when the two girls come together to discover the mysterious secret of why Annaliese's father has to leave, what's going on, and why Annaliese can see demons, things get lethal. Very lethal. Meanwhile, the Gatekeeper, Keeper of Worlds and Immortal Bodies, is up to something, something big and dangerous-- Something that could set the world on its edge. And it's up to Riley and Annaliese, with the help of her mysterious cousin Dylan and a newly found boy named Kolby to stop it.

All in the title

Percy and Annabeth have been through it all, but still managed to emerge as heroes when it all was done, and survived together. But they know that all may not be done as they know of a prophecy that could change the lives of their children lives forever as history repeats.