"Sirius!" said a voice, and he very nearly hit Rubeus Hagrid squarely in the stomach with a Cutting Hex that would have been neck height on an ordinary man. He cut off the reflexive motion just in time, eyes wide with adrenaline, as he wheeled to see the Hogwarts gamekeeper emerge from the blown-out hole of the upper floors, looking grimmer than Sirius had thought he was capable of. "Ya heard?"