omgoshilovemybois
Got this idea from @samigirl101, wanted to add a little spin on it, so here we go!
Percy Jackson has just turned 18 and is waiting for acceptance letters from colleges when Hecate appears to both him and Annabeth, asking for their help. A race of wizards, blessed by her magic though they don't know it, has a wizarding school in England, and Hecate is asking them to become teachers there. Teachers! Apparently, they are to be teachers of a class called Defense Against the Muggle Arts, a class to train the students in all types of combat. At first, they blatantly refuse; teaching for an entire year would make them miss their first year of college after all. But Hecate tells them that they will be safe in a time bubble of sorts; they teach for a year in England but only a couple of weeks pass in America. After they reluctantly accepted the quest, Hecate gifts them with wands, which allow them to cast some limited magic. A quick shopping spree in Diagon Alley later, and they are off! Wish them luck!