What she was telling him made sense in the way that it only could to a wizard. As a Malfoy, Draco had seen strange things since he was a kid. He'd seen unspeakable acts of violence from his father and the company he kept, but he'd also seen annoyingly brave acts from people like Potter and Granger, so he knew that the world was strange and filled with things he would never understand, but what this girl was telling him now made sense.
"I'm not...this isn't my universe," Draco concluded calmly. He tucked his wand into his suit jacket pocket. For the first time since arriving, he was starting to realize that the war-filled world he'd come from couldn't touch him here. Even if this was the same universe--which was unlikely given what this Buffy was telling him--he was an ocean away from Hogwarts and all of the drama that went with it.
He searched his mind for muggle contact methods. "Do you have a..." Draco paused, struggling to remember the word, "phone?" He could enchant it and contact his father maybe.
Then again, his father was the last person he wanted to talk to after failing to kill Dumbledore. But he needed to try something.