He hadn't gone in. The gender ratio in Ravenclaw was severely imbalanced, with far too many young witches. Even as headmaster, he had to avoid suspicion.
He merely knocked lightly on the door. Before long, it opened from within, and Vaughn emerged from Ravenclaw Tower carrying a pleasant fragrance, greeting him cheerfully. "When did you get back?"
He looked as though he were the master of this castle!
Dumbledore was a little displeased. "My dear, if I remember correctly, you're a Slytherin. Why do you always like running off to Ravenclaw?"
"Don't be so nitpicky!" Vaughn replied with a smile, utterly unconcerned. "Do the school rules say that students from different Houses can't visit each other? No, right?"
"Besides, I've always thought dividing students into Houses is highly unreasonable. Forcibly stamping students with House labels is extremely harmful to the harmony and unity of the entire school. Albus, you should thank me. I'm helping the school eliminate a hidden danger!"
"...You really have a thick skin..."
"Thank you. So do you." Vaughn smiled as he retorted, but he did not return to Ravenclaw. He knew that Dumbledore would not have come looking for him without reason.
The two strolled leisurely down the deep, secluded corridor. The faint glow of magical flames swayed overhead, stretching out their shadows.
For a while, neither spoke, as if both were enjoying the tranquility of the late night.
After a long time, Dumbledore finally said, "I told Nicolas about your request."
"Oh? What did he say?"
"In principle, Nicolas likewise does not wish to take everything he has learned into the grave. He is willing to teach you, but before you truly meet and establish a master-disciple relationship, you must first pass his assessment!"
"The exact contents of the assessment have yet to be decided.