Draco was home, indeed. He was currently researching a new development in one of his many potions and he had a cauldron bubbling in one of his empty rooms, covered with what appeared to be potion residue from hours of work. When he heard the knock on his door, Draco brushed most of it off and managed to make it to the door.
Opening it, and without really looking to see who was there, Draco commented quickly, "Make it fast, whomever you are. I've got an important potion brewing in the back that requires my attention."