Who you gonna call? ~Percy Jackson Harry Potter Crossover

Hogwarts is known for having its ghosts, like Sir Nicholas, the Bloody Baron, and Peeves. What happens when Hades, the god of the underworld, finds out ghosts have escaped the underworld to go to a wizarding school in Europe. How will Albus Potter, Rose Weasley, and Scorpius Malfoy react to three strangers who want to...