Percy moves in with his long lost uncle, the great Tony Stark, a year after his mom and step-dad's disappearances. How will things play out with Percy's new girl and his new family. Also can he keep his demigod secret with two prying scientists, three spies, a well-meaning veteran, and an Asgardian who knows more than anyone realizes?

Percy and Annabeth just want a break. Not what Rodolphus Lestrange has in mind when he wants to combine the wizarding magic with the greeks power. Will the wizards and demigods unite? Or will the differences prove too much? Are the heroes even up for this new war? Percy finds he has a hidden sister, only for her to be whisked in the crazy life of demigods.