““Who’s there?” “It is I,” said a low voice. From behind a suit of armor stepped Severus Snape. Hatred boiled up in Harry at the sight of him: He had forgotten the details of Snape’s appearance in the magnitude of his crimes, forgotten how his greasy black hair hung in curtains around his thin face, how his black eyes had a dead, cold look. He was not wearing nightclothes, but was dressed in his usual black cloak, and he too was holding his wand ready for a fight. “Where are the Carrows?” he asked quietly. “Wherever you told them to be, I expect, Severus,” said Professor McGonagall. Snape stepped nearer, and his eyes flitted over Professor McGonagall into the air around her, as if he knew Harry was there. Harry held his wand up too, ready to attack. “I was under the impression,” said Snape, “that Alecto had apprehended an intruder.” “Really?” said professor McGonagall. “And what gave you that impression?” Snape made a slight flexing movement of his left arm, where the Dark Mark was branded into his skin. “Oh, but naturally,” said Professor McGonagall. “You Death Eaters have your own private means of communication, I forgot.””