“Professor, we’ve got to barricade the school, he’s coming now!”

“Very well. He-Who-Must-Not-Be-Named is coming,” she told the other teachers. Sprout and Flitwick gasped; Slughorn let out a low groan. “Potter has work to do in the castle on Dumbledore’s orders. We need to put in place every protection of which we are capable while Potter does what he needs to do.”

“You realize, of course, that nothing we do will be able to keep out You-Know-Who indefinitely?” squeaked Flitwick.

“But we can hold him up,” said Professor Sprout.

“Thank you, Pomona,” said Professor McGonagall, and between the two witches there passed a look of grim understanding. “I suggest we establish basic protection around the place, then gather our students and meet in the Great Hall. Most must be evacuated, though if any of those who are over age wish to stay and fight, I think they ought to be given the chance.”

“Agreed,” said Professor Sprout, already hurrying toward the door. “I shall meet you in the Great Hall in twenty minutes with my House.”

And as she jogged out of sight, they could hear her muttering, “Tentacula, Devil’s Snare. And Snargaluff pods… yes, I’d like to see the Death Eaters fighting those.”

“I can act from here,” said Flitwick, and although he could barely see out of it, he pointed his wand through the smashed window and started muttering incantations of great complexity. Harry heard a weird rushing noise, as though Flitwick had unleashed the power of the wind into the grounds.

“Professor,” Harry said, approaching the little Charms master. “Professor, I’m sorry to interrupt, but this is important. Have you got any idea where the diadem of Ravenclaw is?”

“—Protego Horribillis—the diadem of Ravenclaw?” squeaked Flitwick. “A little extra wisdom never goes amiss, Potter, but I hardly think it would be much use in this situation!”

“I only meant—do you know where it is? Have you ever seen it?”

“Seen it? Nobody has seen it in living memory! Long since lost, my boy!”

Harry felt a mixture of desperate disappointment and panic. What, then, was the Horcrux?

“We shall meet you and your Ravenclaws in the Great Hall, Filius!” said Professor McGonagall, beckoning to Harry and Luna to follow her.

They had just reached the door when Slughorn rumbled into speech.

“My word,” he puffed, pale and sweaty, his walrus mustache aquiver. “What a to-do! I’m not at all sure whether this is wise, Minerva. He is bound to find a way in, you know, and anyone who has tried to delay him will be in the most grievous peril—”

“I shall expect you and the Slytherins in the Great Hall in twenty minutes also,” said Professor McGonagall. “If you wish to leave with your students, we shall not stop you. But if any of you attempt to sabotage our resistance or take up arms against us within this castle, then, Horace, we duel to kill.”

“Minerva!” he said, aghast.

“The time has come for Slytherin House to decide upon its loyalties,” interrupted Professor McGonagall. “Go and wake your students, Horace.”

Harry did not stay to watch Slughorn splutter. He and Luna stayed after Professor McGonagall, who had taken up a position in the middle of the corridor and raised her wand.

“Piertotum—oh, for heaven’s sake, Filch, not now—”

The aged caretaker had just come hobbling into view, shouting “Students out of bed! Students in the corridors!”

“They’re supposed to be here, you blithering idiot!” shouted McGonagall. “Now go and do something constructive! Find Peeves!”

‘P-Peeves?” stammered Filch as though he had never heard the name before.

“Yes, Peeves, you fool, Peeves! Haven’t you been complaining about him for a quarter of a century? Go and fetch him, at once!”

Filch evidently thought Professor McGonagall had taken leave of her senses, but hobbled away, hunch-shouldered, muttering under his breath.

“And now—Piertotum Locomotor!” cried Professor McGonagall. And all along the corridor the statues and suits of armor jumped down from their plinths, and from the echoing crashes from the floors above and below, Harry knew that their fellows throughout the castle had done the same.

“Hogwarts is threatened!” shouted Professor McGonagall. “Man the boundaries, protect us, do your duty to our school!”

Clattering and yelling, the horde of moving statues stampeded past Harry, some of them smaller, others larger than life. There were animals too, and the clanking suits of armor brandished swords and spiked balls on chains.

“Now, Potter,” said Professor McGonagall, “you and Miss Lovegood had better return to your friends and bring them to the Great Hall—I shall rouse the other Gryffindors.”

They parted at the top of the next staircase, Harry and Luna turning back toward the concealed entrance to the Room of Requirement. As they ran, they met crowds of students, most wearing traveling cloaks over their pajamas, being shepherded down to the Great Hall by teachers and prefects.

“That was Potter!”

“Harry Potter!”

“It was him, I swear, I just saw him!”

But Harry did not look back, and at last they reached the entrance to the Room of Requirement, Harry leaned against the enchanted wall, which opened to admit them, and he and Luna sped back down the steep staircase.

“Wh—?”

As the room came into view, Harry slipped down a few stairs in shock. It was packed, far more crowded than when he had last been in there. Kingsley and Lupin were looking up at him, as were Oliver Wood, Katie Bell, Angelina Johnson and Alicia Spinnet, Bill and Fleur, and Mr. and Mrs. Weasley.

“Harry, what’s happening?” said Lupin, meeting him at the foot of the stairs.

“Voldemort’s on his way, they’re barricading he school—Snape’s run for it—What are you doing here? How did you know?

“We sent messages to the rest of Dumbledore’s Army,” Fred explained. “You couldn’t expect everyone to miss the fun, Harry, and the D.A. let the Order of the Phoenix know, and it all kind of snowballed.”

“What first, Harry?” called George. “What’s going on?”

“They’re evacuating the younger kids and everyone’s meeting in the Great Hall to get organized,” Harry said. “We’re fighting.”

There was a great roar and a surge toward the stairs, he was pressed back against he wall as they ran past hi, the mingled members of the Order of the Phoenix, Dumbledore’s Army, and Harry’s old Quidditch team, all with their wands drawn, heading up into the main castle.

“Come on, Luna,” Dean called as he passed, holding out his free hand, she took it and followed him back up the stairs.

The crowd was thinning. Only a little knot of people remained below in the Room of Requirement, and Harry joined them. Mrs. Weasley was struggling with Ginny. Around them stood Lupin, Fred, George, Bill and Fleur.

“You’re underage!” Mrs. Weasley shouted at her daughter as Harry approached. “I won’t permit it! The boys, yes, but you, you’ve got to go home!”

“I won’t!”

Ginny’s hair flew as she pulled her arm out of her mother’s grip.

“I’m in Dumbledore’s Army—”

“A teenagers’ gang!”

“A teenagers’ gang that’s about to take him on, which no one else has dared to do!” said Fred.

“She’s sixteen!” shouted Mrs. Weasley. “She’s not old enough! What you two were thinking, bringing her with you—”

Fred and George looked slightly ashamed of themselves.

“Mom’s right, Ginny,” said Bill gently. “You can’t do this. Everyone underage will have to leave, it’s only right.”

“I can’t go home!” Ginny shouted, angry tears sparkling in her eyes. “My whole family’s here, I can’t stand waiting there alone and not knowing and—”

Her eyes met Harry’s for the first time. She looked at him beseechingly, but he shook his head and she turned away bitterly.

“Fine,” she said, staring at the entrance to the tunnel back to the Hog’s Head. “I’ll say good-bye now, then, and—”