(This was written prior to the release of City of Heavenly Fire and Blood of Olympus.) The war with Gaea is over, and the seven are flying the Argo II back to Camp Half-Blood when who should find them but our favorite New York Shadowhunters, who are caught between CoLS and CoHF. Soon, they find that Sebastian has started doing some interesting things in the demigods' world as well.

Wizards, Demigods and the Shadow Hunters create an unlikely team and depart on a quest, to where; they have no idea. The purpose; they are likewise blind to. All they know is that the world will end if they fail. No pressure! A/N: Used to be When Worlds Merge