Luna left the Room of Requirement first; if something dangerous was waiting, she wanted it to hurt her and not her daughter. Harry came next, dragging the unconscious Sidhe with him. Finally, anxiously, came Harriet.
Harry wasn't sure how long she'd been in the Room of Requirement. It might have been years. Knowing a sidhe was coming for her must have made it hard to leave her haven. As a Gryffindor, he admired her bravery. As a father, he was terrified for her.
"How long will it take?" Luna asked Harriet.
"About ten minutes. Can you make it in time?"
"I think so."
Luna turned to Harry and took his face in her hands. She drew him down to her and kissed him with a desperate hunger that made him, in spite of the danger and fear, react powerfully. She felt him press against her and smiled. She leaned up to whisper in his ear.
"I own you."
With a strange, quavering happiness, he realized she did.
"Ugh," Harriet said. "Get a room."
Luna, still holding Harry, said "Oh, we will."
Harriet fake vomited.
Luna released Harry and crossed the hallway to her daughter. She hugged her, and Harriet stiffly returned the gesture. Luna held out her wand. Harriet took it carefully, nodding.
Luna turned and ran off, her shoes clacking on the stone floor as she went. They watched her go for a moment.
"She can really run in those heels," Harry said, impressed.
"Oh, that's nothing," Harriet said. "When I was four, I levitated my stroller and-"
She froze, staring down the hall in the opposite direction Luna went. Slow footsteps echoed from the darkness.
"You have the captor and captive," Wakefield said, stepping into the light. "No more will need to be killed."
He was covered in dust, grime, and what looked to be human blood. Even his eyelashes were thick with it, but he didn't blink or make any gesture to wipe it away.
"Here," Harry said, hefting the unconscious sidhe with both hands and throwing it down the hall. "Take your friend and go. Otherwise, we shall show you no mercy."
Wakefield barely glanced at his unconscious friend. He snarled at Harry.
"Dad," Harriet said, "'mercy' is an insult to the sidhe."
"Shouldn't you be casting?" he said, standing between her and Wakefield.
She grunted and began. With a wand in each hand, she began a dance-like spell, uttering strange noises. As an academic who studied magic, he found it captivating, haunting, and oddly beautiful.
"Are you hurt?" Wakefield said.
Harry turned back to look down the hallway. Harriet's sidhe was standing up slowly.
"Yes," it said, turning to face Harry and Harriet.
"Excellent," Wakefield said. "It will make the revels all the more sweet."
"Last chance," Harry said, pointing his wand at them. "Go back to your world. This doesn't have to end badly for you."
"Sidhe never end," Wakefield said.
Harry attacked. He strode forward, throwing spell after spell at them. He started big: avada kedavara, crucio, confringo. The spells hit their marks but did little but push them back a few steps.
Harry looked at where he was in the hallway and muttered something under his breath.
He switched tactics, trying smaller jinxes and curses, hoping to keep them off balance by their sheer number and speed. Bee stings. Ice. Slugs. Pumpkin heads. Again, they stepped back a few steps, but it didn't seem to hurt them.
He tightened his grip on his wand. It still hadn't recovered. It wasn't moving fast enough, wasn't powerful enough.
"Shall we attack?" Wakefield said.
"Yes," the other sidhe said. "Let us respond in kind."
Harry saw the green light of the killing curse too late. He'd known avada kedavara well his whole life, but somehow this one caught him by surprise. Perhaps it was because Wakefield had no wand. The magic just seemed to emanate from inside him. Perhaps it was because it was aimed at Harriet instead of him. Whatever the reason, he was too late to react.
His wand reacted for him. Moving on its own for the first time since he used the killing curse in the forbidden forest, it leapt up and blocked the spell.
Harry was stunned. Wakefield and the other sidhe scowled.
More spells followed the first. Harry was forced back down the hallway by jets of yellow and red. He blocked as best he could, but the wand was doing most of the work for him. It pulled his arm from side to side, moving in complicated patterns to invoke countercurses faster than he ever could.
He realized what had happened. When he'd been attacked by giant spiders and couldn't stop them without killing, the wand changed. It couldn't protect him with offensive spells, so it became a defensive wand.
It was brilliant.
Harry looked at where he was in the hallway and muttered under his breath again.
It was a distraction he couldn't afford. Fire struck his shoulder, and he hissed in pain. His wand blocked the next two curses, but only partially blocked the third: a full-body-bind. Harry's legs locked together.
Teetering precariously on his feet, he was able to block the boils jinx and the choking curse, but he was off balance. He toppled over. His wand fell out of his hand.
Wakefield and the other sidhe smiled at each other and laughed. Casually, calmly, they walked forward to claim their prey.
"Hey, idiots!" Luna said from behind them.
Wakefield and the other sidhe turned to face her in time to see her throw something. It was heavy and landed between them with a dull crack, breaking in two.
They stared down at it for a moment, then laughed uproariously. It was the vase Min made for Harry.
"Pottery?" Wakefield said. "You throw clay at the sidhe?"
"Not just any clay," Luna said. "Hand wrought clay."
They stared down at the vase again, this time in horror. Even in the hallway's dim light, it was easy to see hundreds of Min's fingerprints covering its surface. She'd spent hours pressing it into the perfect shape. No fire was used. No magic. It was just the force of her two, small hands.
Harriet finished her complicated spell. It shot out like a wave. There was no light, no sound, only a sense of motion that flowed down the hallway towards the two sidhe.
The vase shards reacted.
The first layer of the spell was levitation. The pieces rose until they were chest-height between Wakefield and the other sidhe.
The second layer was duplication. Two shards became four.
The third layer was explosion.
Bits of pottery flew out in all directions. Some bounced off the walls. Most buried themselves within the two sidhe. They screamed in pain. Glowing blue blood sprayed out of several wounds.
The spell triggered a second time. The shards rose. They duplicated. They exploded.
They were smaller pieces now, but far more. They whizzed in every direction, not going far, but many slicing deep into the two creatures. They screamed again, spitting glowing, blue blood. Some shards, Harry realized, were already inside them when they duplicated and exploded.
The spell triggered again. The pieces were tiny now but struck with the same force. The creature he knew as Wakefield was entirely transformed. It no longer looked like a person. The disguise – the skin, Harry realized – was shredded into bits. Underneath was the bloodstained, blue sidhe that had been hiding inside.
The spell triggered again and again and again. The shards were little more than dust, billowing forth. The cloud reached Harry, and he winced back, but it didn't hurt him. While the particles stung a bit, they were still breaking down to smaller and smaller pieces. Soon, they were little more than mist.
The mist transformed. It glowed blue. The blood stuck on shards was being duplicated as well. Soon the hallway was filled with a bright fog.
Luna, cut in a few places from being too close to the flying shards, stumbled out of the fog.
Harry, finally free, jumped to his feet and kissed her. They turned to look at the two figures lying on the floor. The sidhe had been pulverized, turned into a piles of scrap and blood, but their bodies were already pulling themselves back together.
Harry walked past the wall to the Room of Requirement for a third time. This time he said aloud the words he'd muttered twice before.
"I need a room made of cold-wrought iron, a prison that will hold two sidhe until a million years after all life in the universe is dead."
A door formed in the wall and opened. Harry and Luna walked down the hallway to stare at the unconscious creatures. Harry grabbed the Wakefield sidhe by the arm. Luna grabbed the other and dragged it into the Room of Requirement.
Inside, the room was just a dark, grey box. The walls glimmered a little in the glow from the sidhe's blood. Harry squatted next to the two creatures as Luna stood in the doorway and watched.
"While you wait here alone for a hundred trillion years or so, remember that these walls could have been spikes. The ceiling could have been a giant, crushing hammer. We humans are showing you mercy, even though you don't deserve it."
The two creatures weakly screamed in rage as Harry walked out. The door closed behind him, and he and Luna watched as it melted away into the wall. The Room of Requirement was gone for good, or, at least, it wouldn't open again within their (or anyone's) lifetime. The seventh floor would forever after be a disappointing mystery to Hogwarts students. They'd never know why a whole floor was devoted to an empty hallway.
The cloud still filled the hall, glowing faintly blue. Harriet's spell would continue for years, maybe forever.
"Harry," Luna said, "did you forget that 'mercy' is an insult to the sidhe?"
"It seemed a more appropriate farewell than 'fuck off,'" Harry said.
A shout made them both jump and stare. Harriet - kneeling on the floor with her hands on the wall to the former Room of Requirement - was screaming. She took in a deep, shuddering breath.
And she screamed again.
It was a long, drawn-out scream of anguish. It was if all the pain and misery she'd endured was trying to force itself out her throat. She drew in another breath like a drowning woman gasping for air.
And she screamed again.
Harry thought she would cry, but her face, though red, was dry. She drew in another lungful.
And Luna grabbed her, wrapping her arms around Harriet. Harriet struggled to pull free of her mother, slapping ineffectively at Luna's arms and hands. Luna - calmly, inexorably – pulled her away from the wall.
Harriet screamed again, but it was more a strangled cry than a full-throated howl. She struggled more, but, eventually, let Luna put Harriet's head on her shoulder. Luna hugged her, rocking back and forth on her knees.
"Hush, baby," Luna said. "Shhhhh."
Harriet screamed again. Luna didn't flinch away. She just kept rocking her back and forth.
"The itsy, bitsy spider went up the water spout," Luna sang.
Harry was familiar with the muggle nursery rhyme; Aunt Petunia sang it to Dudley, once. Luna held up her thumb and forefinger and turned it back and forth. Harry knew this was wrong - you needed two hands to make the spider climb - but Harriet seemed captivated. The scream became a low whine.
"Down came the rain," Luna sang, making the second gesture (again, with just the one hand) "and washed the spider out."
Harriet had fallen silent.
Luna stopped, hand poised for the next gesture, but didn't sing. The silence stretched on.
"Up came duh sun," Harriet sang, her voice childish, "and dried up all duh rain."
Luna made the half-gesture of the sun rising. She held up her thumb and forefinger again and waited. Slowly, shakily, Harriet raised her maimed hand. She held up her thumb and forefinger to Luna's, and Harry understood. They had their own version of the song. They had always made the hand gestures together.
Harry thanked all the forces that ruled the universe that they'd let Harriet keep the two fingers she needed to complete the spider.
"And the itsy, bitsy spider," mother and daughter sang together, making the spider climb again, "went up the spout again."
And Harriet cried for the first time since Harry met her.
"Harry," Luna said, holding her hand out to him, palm down, "come meet your daughter. Come meet our little girl."