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.”
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.”
The battle had moved beyond screams. It had settled into a low, grinding roar punctuated by the crack of spells and the shriek of collapsing stone. Harry, hidden under his Invisibility Cloak, pressed his back against the cold wall of a corridor off the Grand Staircase. Dust motes danced in the eerie, spell-lit gloom. He could hear Ron and Hermione breathing somewhere to his left, hidden beneath a different Cloak—the one his father had once used, now mended.
“It’s the only way to end it,” Harry said. Harry Potter And The Deathly Hallows Part 2 -20...
“The diadem,” Harry whispered, his voice barely a thread. “Rowena Ravenclaw’s. It has to be here, in the Room of Hidden Things.”
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.
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. She looked at Harry one last time
“Professor,” Harry started, “the diadem of Ravenclaw. I need to find it. It’s a Horcrux.”
Hermione’s hand found his arm in the darkness. “Harry, the Room of Requirement is a trap. Draco Malfoy already tried to bring Greyback in through there. It might be swarming with Snatchers.”
Ron clapped Harry on the shoulder. “Blimey. I think she likes us.” Potter
The echo of her footsteps on the marble stairs faded, replaced by the thundering of their own as they ran toward the Horcrux, toward Voldemort, and toward the end. End of scene.
“That will take you directly to the seventh-floor corridor,” she said. “It bypasses the Grand Hall and the west wing, where the worst fighting is. Once you’re there, you’re on your own. I have a school to defend.”
A figure emerged from the swirling smoke at the far end of the corridor. It wasn't a Death Eater. It was Professor McGonagall. Her hair had come loose from its tight bun, and a long gash bled freely down her cheek. Her wand was raised, but not in a fighting stance. She was searching.
“We’re not about to start now, Professor,” Ron said, gripping his wand tighter.
“Then we go through the walls,” Ron muttered. “Literally. We know the secret passages behind the tapestry of Barnabas the Barmy. We can get to the seventh-floor corridor from the fourth-floor balcony if we use the old servants' stairs.”