Daydreamer30035
Thalia, Percy, Nico, Annabeth, and Hazel pose as Hogwarts students. Hecate is worried about how her pet world may react after the Battle of Hogwarts, so she sends them in.
The Golden Trio and friends come back to Hogwarts to get a real last year of education. When five new students show up unexpectedly, they are naturally suspicious and on edge.
(Clearly none of this is legally mine. All the rights are to J.K. Rowling and Rick Riordan. All I own is the story plot.)