"I felt the..." How had Gabe put it? "The magical lock-pick grease before the djinn noticed I was there." He wasn't sure if that helped or not, but perhaps it could tell Gabe if the intention was merely to break in or to break out again repeatedly. "I suppose any wards on the door leading to the classroom are, ah...defunct."
Well. There was one more thing. "It's possible," he said reluctantly, "that if you need to test something that had been in the room when I arrived during the siege but which has escaped destruction and further tampering since... I might be able to provide that."