"Could it be just your imagination?"
"Possibly."
"That's likely the case. This is First University's museum, with two The Door Gods standing guard outside. How could anyone sneak in here?"
"Didn't we just get in here?"
Although the young wizards were still whispering in low voices and discussing it heatedly, their eyes remained vigilantly fixed on several of the darkest corners of the exhibition hall, never slacking, and the Law book in their hands was always ready to be activated, able to throw out a prepared string of spells at any moment.
Xiao Xiao held the Crystal Ball in both hands, divining for a long time with no results.
"Perhaps the Monitor did hear something," he eventually voiced a cautiously optimistic view: "It's said that several Ghosts, belonging to the Earth-bound Spirits, are permanent residents of the museum's exhibit halls; the noises we just heard might have come from them."
This explanation wasn't perfect, but it was sufficient to calm people's nerves.