'You will rarely be caught in a lie your victim wants to believe. He would rather make the lie come true than expose you." - Lucius Malfoy

"What I'm trying to get at," Harry Potter said to the gathered Bayesian Conspiracy, located in the potions classroom near Slytherin, "is that the fastest course of action is to make the boldest prediction possible, then experiment."

Neville asked "What do you mean by bold?"

"I mean something simple, something powerful. The old theory of planetary motion stated that the Earth stood still and everything else moved around it. But that meant planets sometimes changed directions. That theory worked, but had lots of convoluted answers and math. The newer, bolder theory placed the sun at the center. It made predictions that allowed easier calculations."

"But what if that theory had been wrong?" Daphne asked a lot of clarifying questions, which Harry appreciated. She'd made a great addition to the group for that reason alone. "I mean, that theory was correct and happened to be bold, but what if the right theory was timid?"

"Well, if you make a bold prediction and are wrong, you tend to be wrong quickly," Harry said. "I lost days trying to fine tune a prediction last year, when an hour of work would have told me I was wrong. In the case of an incorrect bold theory, you typically discover a counter example quickly, and then can go back and think. It's not that you'll be right every time, but when you are wrong you'll gain insight into the problem, and hopefully won't waste as much time."

Draco and Gregory headed up the stairs, towards the offence classroom. Draco taught again today, leading the discussion of how Ginevra Weasley's Genies had destroyed Nicholas Martin's Manticore Army and Zacharias Smith's Spectres. First year Generals had been advised to take unused army names and once "Ginny's Genies" had formed the other two stuck with the best alliterations they could think of that could be considered fearsome. Like Draco feared, the battle – such as it was - hadn't been close. He didn't relish talking about it for the next hour and a half. Weasley's army had faked being dead as had Smith's army. But, unlike Zacharis Smith, Ginny had thought ahead and issued a standing order to shoot dead enemies again, 'just to be sure.'

Gregory had insisted on going with Draco. In theory, to protect Draco from another ambush, everyone knew Draco lectured today. In practice ...

"Look," said Gregory, "Montague and Flint are good chasers, Bletchley's a solid keeper, if a bit uninspiring, but I just can't work with Peregrine. I mean, he's a good flyer, better than Vincent even, but I just never know what he's going to do."

"You can hardly expect to build up the same rapport in a few days. Who is the other chaser?" asked Draco.

"I think it's Warrington, but he's rubbish. Won't be good for another year, at least. I just don't know what to do with Derrick. I realize we've only had five days, but he has the strangest ideas about what the beater position entails. Although I suppose it's all up in the air this year, isn't it? Two forty-five minute halves? Who thinks of these things?"

They went up another flight of stairs, in the distance they heard a crash and Peeves shouting. The first years were probably behind them and didn't know the poltergeist's typical ambush points. "Well, Gregory, take some comfort that Vincent is complaining to Hufflepuffs about their other beater, uh …."

"Rickett," Gregory supplied. Right, thought Draco, Anthony Rickett. He tried to visualize Rickett. Tall for his age, but that may just be an early growth spurt. Brown hair, kind of weaselly look. The animal, not the family.

"Anyway, I'm sure that Vincent has spent the last week complaining that Rickett isn't a bad guy, but he's no Gregory Goyle." The walked past a landing, sunlight streamed through a small vertical slit of a window, with a tapestry hanging besides it. Draco stopped and examined it, then spun around.

"That is one ugly thing. What are you looking for anyway?" asked Gregory. The tapestry depicted a bunch of Trolls and a wizard wearing bright pink robes demonstrating en pointe to the trolls, who watched attentively, with minimal drool. Draco stood facing the other direction, but there was just a blank wall, the rare bit of empty space this high up. Normally the walls displayed paintings, tapestries, windows, dangerous ledges, or some knick-knack. But this hallway had ten solid empty feet, with nothing. Draco ran his fingers across the wall, feeling along the seams.

"I could have sworn there was a restroom here last week," said Draco. "Right between those suits of armor. I mean, I used it – really nice, better than the Prefect's restroom that has the heated pool - and I definitely recognize the tapestry," he waved back behind him. "I'm sure it was here."

"I don't imagine you could forget that," said Gregory, examining the background. "This will haunt my dreams, ah! Duck!"

Draco crouched down as several spells flew over his head. He glanced to the left and saw the Carrow sisters, Flora and Sheila poking around the corner firing spells. Hestia stood in a doorway on the right with another older Slytherin girl, Viola Richmond. What was it with the Slytherin girls? And didn't anybody aim for the chest anymore? Center of mass, hard to dodge. Maybe they just had terrible aim. Gregory dove across the hallway, firing blindly, and pulled himself behind the suit of armor for cover. Draco reached into his cloak and touched the vial of liquid luck, then put it back. This didn't seem that desperate.

"Retreat back around the corner on three," Gregory said and pointed his wand down the hallway and counted "one, two, Jellyfy." Draco ran the few steps to the corner and turned left into the pack of Slytherin boys.

"Oh, cra..."

Gregory heard Draco's shout, and then the Petrificus Totalus and then nothing.

Gregory fired off a few more spells at the now retreating girls and looked back at Draco's body, visible from the waist up as he'd fallen backwards.

"Goyle? This isn't personal. We all like you, Gregory," Marcus Flint's voice carried around the hall, "And we just need to teach your friend some manners. But you can walk away."

"You don't really expect that, do you Marcus?" Gregory shouted, then glanced at down the hallway. The ladies were slipping away. He didn't bother firing on them, but moved to get cover towards the corner.

"No, not really. But we are teammates and I," the words ended with a sickening crunch and some shouts, a stupefy, a curse he didn't recognize and Hermione Granger shouting Glisseo. There were several more shouts in response followed by the sound of tumbling. Gregory ran – no point in dodging when the enemy had no line-of-sight – and crouched over Draco's body then peeked around the corner. Marcus Flint stood doubled over, bleeding from his mouth, lower lip even larger than normal and one of his front teeth twisted slightly.

Gregory pulled Draco out of the line of fire and saw Lucian Bole, who Gregory had just taken the Beater position from, down on his hands and knees but still firing curses at Hermione. Terence Higgs, former seeker, cast an Expelliarumus and hit Granger squarely with it, her wand flying down the hall. Hermione just got up and started running towards Higgs. Gregory hit Bole with a Somnium just as Hermione slid into Higg's legs, knocking him over like a set of tenpens. They rolled over each other along the ground and then she was on him, throwing punches into his stomach.

Boles let out a few grunts and Hermione wrestled his wand away from him, barely pausing before leaping up and breaking into a graceful run. By this point Marcus had recovered and, spitting out his tooth, cast Protego. Gregory's stupefy was well aimed, but hit shields. Hermione cast a few Laganns and Gregory followed suit, but Marcus's shields held and he fired a powerful Ventus towards Gregory that sent several paintings flying off the wall, complaining loudly about students today as they clattered to the floor. Gregory ducked back just in time to see Hermione swinging through the air, legs around Marcus's neck, then her momentum flipped him off his feet just as she released her ankles and then landed next to him and simply kicked his wand away before hitting him with a stupefy.

"You've got to be kidding me," Gregory said under his breath. He walked over to Draco whose eyes followed his movements. Gregory cast finite incatatem. Draco popped up quickly, taking in the scene, while Gregory recovered the scattered wands.

"There were a few more on the stairs," Hermione said, "but I didn't see them before they slid away. Sorry. I guess it would have been useful to know who they were. But better safe than sorry." Gregory tossed Hermione's wand to her. "Thanks, Gregory."

Draco walked up to Hermione. "Are you all right? Thanks," he said, somewhat bashfully, "for everything." Draco inspected Higgs and Flint, both now moaning slightly, then stood up and looked at Hermione again. "If you want, I can fix up that bruise so it doesn't show until you can get it taken care of."

"No, I'm fine, Draco. It's lucky I was here."

"Yes," said Draco, "very lucky."

"No," said Gregory in an excited whisper, "there's no way she could do that. I couldn't do that move, it requires a good decade of martial arts training. That's Asian quality Shaolin type stuff. No way Hermione Granger just learns that." They were walking back after both offence classes, Draco lecture and the second year class. They'd stopped by the tapestry again and Draco asked Gregory to walk him through what happened - another after-action report, like the one he'd lectured on to the first year students.

"And yet she did it," Draco said quietly. "Or you imagined it."

"I did not imagine that," Gregory started and Draco just shook his head.

"No, I believe you, she really did it. You saw it, it's true. And you are confused." Draco let the words hang in the air as they walked down another flight of stairs. "How did her hair look? How did she look, while fighting."

Gregory considered. "I didn't get a good view, but I'd say normal. Why?"

"You said she tumbled on the ground, tackled Higgs and rolled and punched him. But she had no dirt or dust on her. Just one bruise. Her hair looked perfect, not even mussed, when I looked at her. I thought - I don't know - I thought I was infatuated with her."

"I'm infatuated with her right now, too," Gregory interrupted.

"Yes, I get that. I think I still am. But I think it's not just infatuation. I think she's got a glamour to keep her hair nice, repel dirt, the works. I mean, I can do all that but it's not permanent. If I'd gone flying through the air my hair would mess up. And she also has a glow. Maybe she's got some other spell that makes her graceful. She wasn't sweating, either, although the fight ended so fast that doesn't really mean anything."

Gregory nodded. "Yeah. Yes, that sounds right. And she was graceful, like you said. How did you know?"

"It's why I believe you. When I got hit, did you notice anything unusual?"

"I wasn't looking that way. I was covering you, remember? But you were awake when you the fight was over. But that spell doesn't put you to sleep..."

"It does if you hit the ground hard enough," said Draco, "but I didn't hit at all. Something caught me right before I hit the ground, then lowered me. It had to be her, unless we're saying there was someone else around. And, I'm not sure but I think she caught me with her foot." Draco remembered last night's lesson. "Do we have a bold prediction on what's going on?"

They walked along in silence for three flights of stairs.

"OK, let's just assume that she's become pretty amazing," said Gregory, "which we already knew, after Azkaban."

"Assuming Azkaban is true," said Draco, "which now seems likely." Gregory nodded. "She was always anti-bully, so maybe she's just lurking around to wreck vengeance on them."

"And not," said Gregory slowly, "following us around because Potter asked her to."

"Invisibly," Draco added.

"With martial arts skills I don't have after six years of training," Gregory said.

"That she never showed last year," finished Draco.

They walked back to the dorms in silence.

Horace Slughorn stared over his assembled Slytherin students, those who had been marched from the Headmistresses office after being caught for attempted bullying. They weren't impressive – even ignoring that they'd lost to a second year girl, albeit The Girl Who Revived – but he couldn't tolerate the pettiness, the lack of ambition.

These weren't ringleaders, the clever rarely got nabbed in the first sweep. These, he reflected, were minions. But as he looked along the worried faces, Professor Slughorn suspected the instigators would hear everything he'd say soon enough. He'd had the Headmistress send the bruised and defeated students to his potions classroom instead of meeting them in the dungeons, because the long walk allowed time to worry. He'd finished brewing a particularly nasty draught of Baneberry potion, room smelling pungent as if a fire burned rotting flesh that left students coughing and eyes watering. It took decades to acclimate to all the smells in a potions laboratory, and only the best Potions Masters could stomach them all.

Which didn't make it any more pleasant for him, but he showed no sign of distress, unlike his charges.

"Flint, m' boy. I'm inclined to overlook this whole thing," said Professor Slughorn, as Marcus Flint's face relaxed into a look of dumb relief, "since I would hate to lose the Quidditch cup as my first year. Oh, that wouldn't do. Wouldn't do at all, no matter how they change the rules. And if I suspend you, well, I'll have to investigate the rest of the team and and where would we be, hmm? Nowhere good." He turned his gaze to the other boys and noted, with satisfaction, their watering eyes. No doubt caused by the thick musk in the air, but if he needed to send them out in public others would assume they'd been crying.

"Still, I can't very well let you off without something. Must keep up appearances. Now," said Slughorn, shifting his considerable bulk, as the chair creaked plaintively, looking down at Flint, Higgs, and Bole, "I find it hard to believe that you have a serious grievance against Malfoy. None of you lost your parents. You might have a slight against Mr. Goyle, Bole, and Malfoy is a convenient excuse. I have my own theory, would you like to hear it?"

Judging from the nods, Professor Slughorn thought that they would.

"Given what I've heard about the attack, it seems that the Carrow sisters, who do have a reason to feel slighted, are offering …. certain incentives, or bounties." As he spoke, Slughorn carefully studied their faces and could tell that he was wrong. The dawning realization on Marcus Flint's face - the slow reveal that he probably could have asked for some favors - spoke volumes. But that same realization also meant that Slughorn had effectively punished those girls far worse than he could in any official capacity. He chuckled, more to himself than to keep up the charade.

"I thought as much. I was a young man, myself, and it's a rite of passage to allow yourself to be manipulated by some witch. You know the old saying, 'You can't fall into her arms without falling into her hands.' Ha! But, at some point you must be your own man. Why, get a reputation for doling out favors for any witch who just smiles at you ... well, you aren't a true Slytherin."

Terrence spoke up "Sir, it's not just..." Slughorn silenced him with a stare and a harrumph. He'd get the exact reason later, in his own time.

"I'm sure it's not just that, you may very well have legitimate complaints. But I expect them to be solved quietly. And I don't expect to listen to them myself, not today. If, in a week, a quiet week, you have complaints I'll take them up. But for now I want peace and quiet in my house. So I think we'll settle for just having you clean up this room as part of a detention, instead of discussing expulsions. Oh yes, I'm perfectly willing to clean house. And I find a more concrete mild threat now will often work when a distant but much greater threat doesn't."

"Greater threat, sir?" asked Boles.

"Why, with Lord Voldemort dead I can only think of three future dark lords, and you've managed to annoy them all during the last few weeks," said the Professor, easing out of his chair. "Scrub the glasswork well, and be sure not to spill any potions on you. It will burn through your skin. Give you some raging acne if you sniff too much of it, now that I think of it. You all know where everything goes, and I daresay it won't take you much more than four hours. I'll come check back after dinner." He strolled out the door.

"Three?" said Martin, as they glanced among themselves.

"Three?" said Gregory, sounding surprised.

"That's what Slughorn told them," said Daphne Greengrass, who'd heard about the entire incident the day before. The entire dating relationship of the upper classes had gone through a period of turbulence over the last twenty four hours, including numerous slaps, hexes, curses, pleading and breakups, although a few new relationships formed as well. The witches gossip network nearly collapsed from the strain of keeping up. "Said there were three future Dark Lords. I mean, I can see Potter and Draco, no offense."

"None taken," said Draco, with a small bow, where he sat on his bed, perusing the latest letter from Mother, "although I think he was just trying to convince them to back down."

Daphne, sitting in Draco's chair at the desk, nodded. "Well, obviously, but that still begs the question as to who the third Dark Lord would be."

Gregory paced slowly. "Granger? I mean, I can't see it, although it would be somewhat great," Draco looked up at him quizzically, "I mean, come on. A Dark Gryffindor? With a Phoenix? And she likes us. We could do a lot worse, you know," Draco went back to reading his letter with a sigh and Daphne just shook her head. "I did say somewhat great," Gregory said, morosely.

"If it were me," said Draco, "it would just be a mind game. Slughorn didn't mean anyone in particular, he just knew that everyone expects there to be one or two, so by saying three he makes them all stop and think. Which is probably a novel experience for them, but sadly not habit forming. In any case, I can't think of another credible Dark Wizard of our generation..." Draco's voice trailed off for a second, then picked back up. "I mean, certainly we could have one, but nobody seems like a threat yet. No, he was just messing with them."

"You sound like you've just convinced yourself," said Daphne. "But you haven't convinced me. In any case, I figured you'd want to know. Do you have any idea why they targeted you?"

"Thank you," said Draco. "As to why, simply because they can. They've gotten a few shots in, but not enough to claim victory. Now it's more about honour than any reason."