"Hagrid did what he was told. I never could figure out why McGonagall send us out there. It wasn't like her. I think Dumbledore told her to send me there at the first opportunity and she did what she was told." It made sense and it would explain her decision.
"I know," he said, quietly. "Hogwarts does strange things. If it moves stairs and changes room while you're in it, why not this?" The thing that bothered him was that Hogwarts had a tendency to give you what you needed. Why would they need this? "Are you planning on asking every possible question? Because you should have come here with Hermione. I'm the one who waits until something is trying to kill him so he can defend himself."
For a moment, he thought about telling Malfoy to go back where it was safe, but they had no idea what was happening and Malfoy was safer with him. "Forget about the changes. We can worry about those later. We're here." He pushed the door with his left hand, his wand still on his right. "We'll get some answer soon, but for now, I suggest taking your wand out. We don't know what we'll find and I don't have eyes at the back of my head."