Harry hesitated, then pulled the Cloak from his head. Ron and Hermione did the same. McGonagall’s eyes widened for a fraction of a second at the second Cloak, but she didn't comment. She strode forward, her tartan dressing gown (she had been roused from her chambers) billowing behind her like a battle flag.
Harry took one last look at McGonagall’s retreating figure—small, indomitable, a lioness in tartan—then pulled his Invisibility Cloak back over his head.
She looked at Harry one last time. Her eyes were wet, but her jaw was set like flint. “Mr. Potter. It has been an honor to be your teacher. Now go. And for Merlin’s sake, win.”
Harry opened his mouth to thank her, but she had already turned away, her tartan dressing gown snapping as she marched back toward the sounds of battle, shouting a hex that turned a section of falling ceiling into a flock of angry, razor-beaked sparrows.
McGonagall was silent for a long moment. Then she did something unexpected. She lowered her wand and smiled—a thin, fierce, terrible smile. “You have your mother’s eyes, but you have James’s nerve. Foolhardy, reckless nerve.” She looked past him at Ron and Hermione. “And you two. You never left him.”