Sherlock had to be casual with Weasley to get past him to the Astronomy Tower, but Sherlock wanted to kill him. How had Moriarty gotten past a full blown Auror—a Hero of Hogwarts no less—with a likely struggling John in tow? Was he being intentionally incompetent? Sherlock was starting to wonder if he should invent a way to stay teenaged forever, because clearly adults lost all their usefulness when they grew up.

Sherlock was ready with a shield spell the moment he went through the door to the top of the tower, but Moriarty was too quick—Sherlock's wand flew from his hand and was caught by Moriarty.

Sherlock's gaze locked in on the four people tied up on the roof: John, Molly, Lestrade, and Mycroft. They were all very alive, however, and seemingly completely unharmed. He'd not even had to knock them out, he'd so easily overpowered them. They were all tied up with their backs to each other, cloths stretched across their mouths to gag them.

Sherlock met eyes with John, who clearly looked frustrated with Sherlock having come at all, considering that Moriarty wasn't even pretending it wasn't a trap.

But John was truly an idiot if he really thought Sherlock'd not come for him. He'd gladly run into danger a thousand times over if it meant saving John.

Moriarty wasn't attacking him, which meant he wanted to talk. That was good. The longer they talked, the more time Sherlock had to manipulate the situation in his favour. "Why take the others if your quarrel is with Muggleborns?" asked Sherlock, stepping forward with his hands behind his back.

Moriarty gave a smile, one that Sherlock had learned to be wary of years back. It was charming to everyone else, but Sherlock saw the madness glinting in his eyes. "Oh, my quarrel was never with Mudbloods," said Moriarty. "They're a minor nuisance, sure, but I don't care what they do, really."

"So did you lock them all in the Chamber out of boredom?" asked Sherlock sceptically.

"Well it was fun, wasn't it? You had fun, I'm sure. A grand adventure. Surely you'd been waiting for it to come to this all along."

"And I actually thought you were clever enough to have a real plan up your sleeve," Sherlock muttered, shaking his head. "Just a madman after all."

Moriarty wasn't fazed. If anything, his sneer widened. "Oh Sherlock, none of this was about boredom. It just wasn't for the reason you thought."

Oh good, he planned to monologue. This was going quite well so far. "And what was the real reason, pray tell?"

Moriarty's face grew stony with one of his frequent shifts in mood, but his smirk stayed in place as he said quietly. "You."

Sherlock rose a brow. "Me?" he asked sceptically.

"This was all for you, dearie. From day one."

"Right."

"Oh I mean it, Sherlock. If you'd not fallen for this one," he said, jabbing a thumb at John, "I'd never have taken them in the first place."

Sherlock was starting to wonder what exactly was going on here. Misdirection? Was he trying to make him angry, keep his mind muddled? What was the point in saying this?

"Clearly you're not getting what I'm saying, love," Moriarty crooned, "so I'll just explain. Please hold all questions until the end, yeah?"

Sherlock just glared, so Moriarty continued, "You knew I was a Dark wizard from your first year. As young as you were at the time, you weren't even sly about it—you told everyone what you thought I was, and when word got 'round to me, I was intrigued. You knew so fast who I was, but how?

"I kept a close eye on you after that, and I knew that you had a penchant for mysteries. So I thought, why not test his wit? I killed Sabrina Morgan to see how quickly you would implicate me, and you did not disappoint. I mean, if I had to be at this wretched school as long as I did to be trusted at the Ministry, then I might as well have fun while I waited, right?

"I didn't let you forget about me, of course, so I continued to play little tricks on Mudbloods, just little love notes to you—and you did love them, didn't you? It was exactly the mystery you craved.

"I knew it would have to end well for you to be satisfied, but how to do it? You didn't have a vested interest in anyone at the school. Adler was clearly an idle dalliance.

"And then, bless his soul, John Watson came around, and it was perfect. I could really make you tick once you started to fall for him, and it was delicious to watch you dance. I even got a little too excited and tried to kill him that one time—impulses can be so hard to control sometimes.

"But I knew that just killing him was thinking small. I had to give you a mystery—a huge one, one for the ages. I mean, at that point my plan at the Ministry was going swimmingly, why not play a little game? It's not like they'd miss me for a couple extra months. You were going to save the Muggleborns, and I was going to congratulate you, and then I was going to take my place as Minister and all would have been well. You were relishing in it, even—I left Molly around as an extra piece of the puzzle, but I never imagined you'd actually torture her to get the memory back!" He let out a mad back of a laugh.

"I thought right then and there that you were the most wonderful person I had ever met—finally, a worthy adversary, and in a child too! It was too good."

He'd related all this with a smile on his face, and Sherlock just watched him, keeping his face stoic. But now, the rage was coming back. His face twisted with it. "And then," he said quietly. "And then, you SPOILT EVERYTHING!" he roared. "You would've had everything, Sherlock. A place in my Ministry once you graduated—power, glory, I may even have let you keep your Mudblood puppy… but then you somehow got hold of the Ministry. Of Harry Potter, that dull angel, and you ruined a plan that was more than TEN YEARS IN THE MAKING!" His nostrils were flared as he looked at Sherlock with wild eyes. "I had you so distracted with the Mudbloods that I was sure the Ministry wasn't even on your mind. McGonagall tried to get to them, but I expected as much and she was ignored as planned. But somehow, even after all my precautions, those damn Aurors were informed and now you've taken everything from me, Sherlock. All my work, decimated. I've got nothing left, nothing in the world, but to finish this game with you. And I'll burn you. I'll burn the heart out of you." The corner of his mouth twitched up. "And I'll do it," he said, his arm slowly elevating until he was pointing at his friends, "through them."

If Moriarty paused for Sherlock to say something, he was going to be disappointed, because Sherlock couldn't think of a response to all he'd just heard. Everything that had happened to the Muggleborns, to Molly—to John, his John—was because Moriarty thought it was the mystery he'd always craved? As a sick sort of gift for being clever?

There were no words to relay how repulsed he was.

But Moriarty wasn't done.

"Maybe I should start with Molly," he continued. "If I torture her for even a few moments, she'll lose her mind, after what you did to her. How would you like to see her mind break right before your eyes?"

The thought of it left the permanent hole in Sherlock's chest gaping and burning.

"Or I could start with Greg—so kind, so trusting of you. Or your brother, the one you've only just become fond of. It would all be rather fun, wouldn't it?" He gave another grin.

"All I know is that John will go last, and that after you watch what I do to him, you'll want to be dead. And I'll oblige, yes, but only when your heart is a smouldering mess in your chest."

Sherlock's breathing was ragged at the words, emotion ripping through him in a way he never thought it could. These were the only people in the world that cared for him, that he cared for himself, and Moriarty was going to torture them all into madness before Sherlock's eyes.

John was looking at him again. There was no fear in his eyes. If John were scared, that might've made Sherlock feel even more hopeless, but the fact that he believed in Sherlock—believed that he would get them out of this—filled Sherlock with determination.

He knew what to do.

"Oh, I see," Sherlock said breezily. "You're just afraid to deal with me yourself, because you know I'm cleverer than you. That I'll only stop you again."

Moriarty turned slowly to Sherlock, his face pulled into an impressive scowl that made Sherlock's skin crawl. "I see what you're doing Sherlock. It won't work."

Sherlock ignored him and continued, "You know you can't beat me unless I'm crippled by grief."

"Sherlock, don't be boring."

"I'm clearly not boring at all, seeing as you couldn't beat a fifteen year old. It's kind of laughable, you know?"

Moriarty's mouth was twitching. He didn't want to admit Sherlock was getting to him, but he could see it.

"I just mean… it's a little tired, isn't it?" Sherlock asked. "You torture my friends, I cry a bit, then I throw myself off a tower. There's no fight, no flair. If you wanted the mystery of the century, you can't well have the climax fizzle out, can you?"

Moriarty's brow went up. "Then what would you suggest, darling?"

"All fairy tales have to end in a fight scene, right? A duel. No Unforgivable Curses. Just you and me."

His eyes narrowed. "What's the point? I'll win."

"And that kind of overconfidence is exactly what always slays a giant."

His mouth stretched into a grin. "Well, it is more interesting. I'm very cross with you still, but I suppose for old times' sake, we can do it your way. But if we're not fighting to the death, then what happens afterwards?"

"Come now, I'm having all the fun. You decide."

He looked thoughtful. "When I win, I get to play with your friends, and when you beg me for death, I'll allow you to jump off this tower."

"And when I win?" asked Sherlock.

He smirked. "If you win, then I'll throw myself off this tower. And boy, will you miss me when I'm gone."

It was better than Sherlock could've hoped for. He'd agreed to not having Unforgivable curses, which was good—if he cheated, he won't have actually won, and he had too much pride for that. As for whether he actually leapt off the tower… it was in question, but it was the best Sherlock was going to get.

So Sherlock stepped forward with a hand out to shake. "Deal." Moriarty's grin was devilish as he took Sherlock's hand. Then he handed Sherlock his wand.

They bowed to one another, even though Sherlock felt sick giving Moriarty that kind of respect. But the game had to be good or Moriarty would get bored. He had to play the part.

Sherlock made the first move, throwing a disarming spell at him. Moriarty blocked it easily. Moriarty flicked his wand at Sherlock, and Sherlock blocked him using Protego. The fight sped up, but neither of them could get a proper hit in. Sherlock had been confident he could hold his own long enough to think of a better idea, but he ended up being more evenly matched with Moriarty than he expected.

Sherlock considered, for a moment, breaking the rules himself and just using the Killing curse on him… but his chest hurt too badly in response to that thought. He wasn't sure he'd get the words out before the pain was too much to manage and he couldn't risk not killing him in one shot.

He had to think of something else. Something would come to him. It always did.

"Sherlock, please," Moriarty said after a moment as he blocked another spell. "This is getting boring. Try a little harder, will you?"

And that was when Sherlock realised that Moriarty was toying with him. Again. They weren't evenly matched. He was just dragging it out.

"Seriously, I'm going to start cursing your friends right here and now if you don't make this interesting."

Sherlock glared, flicking a spell quicker than before. Moriarty had to sidestep to miss it. "You wouldn't dare," Sherlock spat.

"We made no rules about hurting your friends. Maybe you should've paid better attention, Sherly."

Sherlock's entire world stopped. He was right. He'd made no rules about that—how stupid could he be? Moriarty could flick the Cruciatus curse at Molly and drive her mad in seconds. He could blow an arm off Lestrade. He could cut a hole in John's belly. A million things.

In that moment of rage, Moriarty was immobile, his reptilian grin frozen in place. He was thinking a thousand thoughts at once and Moriarty wasn't even moving.

Sherlock knew he would hit his mark this time. In fact, he was so sure, he said the spell aloud.

"Expelliarmus."

Far before Moriarty could block it, his wand flew out of his hand and landed in Sherlock's.

It took Moriarty a long moment to realise what had happened. He looked at his own hand in shock, and then up at Sherlock. His mouth flapped pathetically for a long moment, and Sherlock smirked at him.

Moriarty shook his head, eyes narrowed. "No. That can't be. You—you're ordinary."

Sherlock's smile grew. "Oh, that's where you're wrong," Sherlock replied. He stepped forward one step, two. "I am you," he told Moriarty. "Couldn't you see that from the start? From the moment I was able to torture an innocent girl just to get a memory back? I'm you. Prepared to do anything; prepared to burn; prepared to do what ordinary people won't do. You want me to shake hands with you in hell? I shall not disappoint you."

Moriarty stepped forward too as he shook his head, chuckling. Sherlock kept a firm grip on the wands in his hand in case Moriarty planned to wrestle his out, but it seemed a little unglamorous for him.

"Nah." He shook his head again. "You talk big. Naah. You're ordinary. You're ordinary—you're on the side of the angels."

Now Moriarty was right in front of him, and Sherlock wasn't playing a game anymore. Neither was Moriarty. For the first time, they were looking each other in the eye and speaking their minds—no pretences, no manipulation. It was raw, almost intimate. If Moriarty wanted a climax, this was it—the play had gone awry, the curtain was blazing, and all that was left of the show was these two men, glaring each other down and being dismayed to see skewed reflections of themselves in the other's eyes. Sherlock meant every word—he was Moriarty. They, in many ways, were similar. Frighteningly so. Which wasn't to say that Moriarty wasn't partially right. But the fact remained… "Oh, I may be on the side of the angels, but don't think for one second that I am one of them."

Moriarty was looking at Sherlock closely, as if trying to see something in his face.

"No," he finally concluded. "You're not." He began to smile, a Cheshire grin so manic that anyone would've seen his madness now. "You're not ordinary. No. You're me." He huffed out a laugh that Sherlock could feel on his chin, hot and sweet, like he'd eaten a chocolate before meeting Sherlock here. "You're me! Thank you!" His hand hovered over Sherlock's shoulder, like maybe he wanted to caress him, and Sherlock couldn't help but feel like he'd never been in more danger before. They had ended up against the side of the tower, the both of them. Moriarty was going to shove him off.

Moriarty then held out a hand for Sherlock. "Sherlock Holmes," he said reverently. He knew it was unwise, but he was too caught in the moment not to take it—his hand was hot, his pulse was pumping hard through it. He was excited. His grip was tender and damp. "Thank you," Moriarty said. "Bless you."

And while Sherlock had always had a bit of trouble predicting Moriarty's next move, this one—even though they'd previously agreed upon it—was the most surprising at all. Because he let go of Sherlock's hand and, with a smile, leaned to the side—where there was nothing but air.

And Sherlock watched as Moriarty plummeted from the tower, then hit the ground far, far below.

In that moment, he should've been rejoicing, but he looked down at that body, at the one he'd just seen so much of himself in, and have just a moment of mourning. Such a great mind meeting such a dirty, inelegant end.

Though Sherlock, honestly, would've done the same in his place. He didn't have his wand. Sherlock would release the others—and even though they were kids, five of them was plenty to subdue a single unwanded wizard. And then he'd be turned into the Ministry. Moriarty had surely known all that, had seen it in his mind like a film reel… and wouldn't that have been even more disgusting? At least this way things ended on his own terms, having met the protagonist he'd always dreamed would star in his play.

It took Sherlock this long to understand something else.

And boy, will you miss me when I'm gone.

Moriarty had died thinking he was punishing Sherlock. Had Sherlock just met and defeated his greatest foe at fifteen? How disappointing. He'd complain the rest of his life of being bored. Maybe Moriarty even hoped Sherlock would go dark himself, with nothing else that could break the tediousness of ordinary life.

But that's where Moriarty misjudged Sherlock. No part of Sherlock was disappointed with this ending. No matter how many times in his life he swore he was dying of boredom after this, remembering a time when his mind was truly tested, he'd never wish Moriarty back from the dead—because he had more to care about now. He had people he loved and he couldn't risk them for the thrill of the chase. Moriarty thought any sort of love or compassion was nothing but chemicals. He thought Sherlock would rise above it all and become the next antagonist.

But if he had John, why the hell would he ever want to? He and John running 'round and solving even the smallest mysteries for the rest of his life—that was good enough for him. More than enough.

So Sherlock turned away, no regret in his mind, to untie his friends.