"Constant vigilance!"

Harry knew he should be prepared to hear Moody's catchphrase whenever he came within a hundred feet of the Defense classroom, but he was still angry about the conversation he'd just had with Draco, and he was distracted.

He managed to keep himself from actually startling, though Pansy and Blaise, who had caught up to him about five minutes before class, glanced at him. Maybe he hadn't been as subtle as he'd hoped.

"Today," Moody said as everyone took their seats and pulled out their books, "You're going to learn how to keep yourselves concealed when you're on enemy territory."

"And how often, exactly, does he think I intend to wander onto enemy territory?" Pansy murmured under cover of the rest of Moody's lecture.

"And do you think the practical is going to involve portkeying us into Snape's office unawares?" Blaise whispered back. Harry remained silent.

"Not hardly. We Slytherins are more likely to be sent to his private quarters. I don't think it'd matter what House we're in if we caught him in the bath."

Harry paused in his brooding to join Blaise in grimacing at Pansy, and the three of them took a moment to shudder in unison.

"I'm sorry," she whispered after a moment. "I didn't...I'm sorry."

"The Disillusionment Charm is one of the more commonly used methods of concealment in a wizard's arsenal," Moody told them. "So we'll practice that first. Everyone partner up. You'll be casting this on yourselves, and your partner is going to try to hit you with the stinging hex. Your job is to keep out of their sights."

One of the Ravenclaw girls raised their hands. "What if someone who isn't our partner hits us?"

Moody raised his eyebrows. "Then you're hit, aren't you? You'd do best to keep an eye out from all angles. Wizards won't avoid attacking you in battle because you aren't who they were aiming for initially." He glared around at them all. "And the rest of you should be keeping your eye out for friendly fire as well. If anyone's hit, they're out, Disillusioned or no."

"Right," Pansy said, turning to Harry. "Do you want to attack first or shall I?"

"Both sound like so much fun," he said, "I don't know how I'll choose."

"Well, I guess I'll attack first then," she decided, smirking at him. "Off you go. I do hope you were listening when he told us the incantation."

Harry hadn't been listening. It was only his good fortune that he had bothered to open the book up to the right page, and was able to glance down at it before they got up.

"Of course I was listening." He walked over to the side of the room where the rest of the soon-to-be-disillusioned students were going, and listened to the Ravenclaw next to him as he said the spell. Just in case.

Somehow, Harry was the only one of his friends to have ended up on this side of the room, he noted as the spells began to fly. He wasn't sure how Moody expected them to avoid being hit, with that many spells being thrown at them at a time. Harry saw Blaise cackle as his spell hit the Ravenclaw boy. Harry decided to get low and keep moving.

It wasn't difficult to see his fellow attackees. Apparently, this was a spell that only worked if you moved cautiously. Whenever someone panicked and started running, most of the class would focus on the blurred shadow of their form, and take them out. It was just a mild stinging hex (or at least Harry hoped everyone had been sticking to the stinging hex), but still.

He did the only thing he could think to do, and started moving toward his attackers. Inching along the wall was impossible; too many spells were bouncing off them randomly. He'd be hit for sure. Harry saw Draco taking aim about ten feet to his left, and considered what Moody had said about friendly fire. Did it count as friendly if they hadn't been friends for months? Probably not, but Harry thought he could get away with it anyway. He checked to make sure Moody wasn't watching before sending a stinging hex Draco's way and grinning when Draco jumped and glared at the students around him.

Feeling inordinately better, Harry started moving toward the Ravenclaw side of the line, and saw Anthony standing on the end, near the wall. Perfect. As he inched toward him, moving in a half crouch on his toes and fingertips, he saw Anthony glance away, toward the other end of the room.

It was now or never. He managed to slip past Anthony and move safely among the desks, watching the backs of the attacking students. He was safe. Harry sighed in relief and leaned against a desk, only to jump back up as he felt a sharp sting on his shoulder. He took the spell off and looked around to see who had gotten him.

"Sorry, Harry," Anthony said, shrugging and turning back to the rest of the class. "Constant vigilance."

"Potter," Moody said at the end of class, "Stay in your seat."

Harry stopped packing his things up and frowned. Pansy gave him a curious look as she and Blaise put their things away and left with the rest of the class.

Moody limped over to where Harry sat at his desk, feeling nervous. "Do you know the definition of 'friendly fire', Potter?" Moody asked gruffly.

Harry felt his stomach drop slightly. Moody had a magical eye. Of course he would have seen. Harry looked down at his desk and nodded. "Yes sir."

Moody stared at him for a few inscrutable moments, and Harry waited for his punishment.

"You've got a good head on your shoulders, boy," he said finally. Harry looked up at Moody, who was staring at him with both eyes now. "Your first instinct is to attack and to get out of the line of fire, to where your opponent didn't expect you. If this had been a real battle, you would have taken it with those tactics. Do you know what you did wrong?"

Harry began to hope that he was going to get out of this without punishment. "I didn't practice constant vigilance, sir?" he tried.

"That's right," Moody said, then barked, "CONSTANT vigilance." He seemed to take enjoyment from Harry's flinch. "You have a good idea of who you shouldn't trust, but that needs to be taken a step further," Moody said, leaning back against the desk behind him.

Harry wasn't quite sure he knew what Moody meant, but he had an inkling. "Sir?"

"The Malfoy boy's history speaks for itself." Moody's blue eye disappeared for a few seconds, then fixed itself back on Harry. He tried hard not to think about how eerie that was. "Durmstrang would have welcomed him with open arms. Constant vigilance, Potter."

He dismissed Harry, who went out into the hallway still wondering how to respond to that. Having the door closed in his face solved that problem, so Harry went on to his next class, still pensive.

Harry sought out the Quidditch pitch after his classes were over for the day. It was cold and windy, but they sky was clear and he wanted to fly off the stress of the morning.

As he passed the lake, he saw that he wasn't the only one out on a broom. Several Durmstrang students were flying above the water, doing dangerous stunts and laughing raucously.

As Harry watched, one of them leapt to his feet - on the broom - and did a swan dive into the deepest part of the lake. Another flyer dove and scooped his broom out of the air before it hit the water, and they all cheered.

Harry watched until the diver resurfaced and somehow managed to remount his broom, dripping wet, in the cold November wind. The boy was only wearing swim trunks. Harry hadn't realised before, because it hadn't occurred to him that someone would do something like that in late November.

They were all insane. That was all there was to it. Harry shook his head and continued on to the empty Quidditch pitch. He was able to spend about ten minutes flying before he realised he wasn't alone at all.

There was a figure holding a broom and waving at him from the sidelines, and Harry couldn't quite make out who it was. As he dipped nearer, he realised the person's height cancelled out any of his friends, and their robes weren't Hogwarts attire.

"Hello Poliakoff," Harry said grudgingly as he reached the ground.

"Hello Harry." Poliakoff stared at the ground for a moment, then met Harry's eyes squarely. "I apologise for my words yesterday. I was..how do you say…out of line."

Poliakoff seemed genuinely apologetic, which was more than Harry could say of some people he'd had arguments with recently.

"I don't like Dark Magic," Harry said. Poliakoff nodded. "I don't like being abandoned to obnoxious reporters either." Poliakoff nodded again, contrite.

"I apologise," he repeated. Harry sighed. Pansy was going to kill him.

"Yeah fine."

Poliakoff brightened immediately. "Do you want to fly?"

Harry hesitated. "Are you planning to drag me out over the lake and push me off my broom?"

Poliakoff grinned. "If you do not want to go swimming, we can surf instead."

"Listen," Harry told him. "This weather is cold. You Durmstrang types might be used to worse, but at Hogwarts we don't exactly consider negative two balmy. I don't even want to look at the lake right now."

"I didn't mean to surf on the lake," Poliakoff explained, lifting his broom. "I meant in the skies. Come, watch."

Poliakoff mounted his broom and, staying near to the ground, went out into the middle of the pitch. Harry watched him curiously. With extreme care, Poliakoff lifted himself into a crouching position on the broom, and finally stood triumphantly. Harry looked on with interest as Poliakoff used his feet to steer the broom into a patch of wind, at which point he crouched slightly and allowed the wind to carry him halfway across the pitch.

As he passed Harry, he called out to him. "Harry, try it, it is fun!"

Harry couldn't help himself. He mounted his broom and imitated Poliakoff's slightly hunched posture, standing upright. After a few false starts, he figured out how to keep himself balanced and steer with his feet without tipping over and crashing. He was glad none of the Durmstrang boys had realised they were over here, or he would probably have drawn a lot of mocking laughter for some of his more spectacular faceplants.

But soon he was up next to Poliakoff, soaring on the wind.

"This is great!" Harry yelled as he caught a current and sailed past Poliakoff. "I didn't know people did stuff like this!"

They surfed on the lower currents in the Quidditch field, and Poliakoff showed Harry how to turn left and right and even widdershins without falling off. Harry's Firebolt dutifully followed his every movement, even through his boots.

Harry got used to having even less than he was used to between him and the ground, far below. This was the euphoria of flying coupled with a healthy dose of the fear he'd never really developed of heights. The adrenaline rush alone was worth it, in Harry's opinion.

"We have races at Durmstrang," Poliakoff yelled to him. They had long since left the Quidditch pitch, soaring higher and higher to catch better wind currents. "Do you want to try?"

"Sure," Harry called back, and they agreed to race to the edge of the forest. Harry bent his knees slightly as Poliakoff counted down from what Harry assumed was three in what he also assumed was Bulgarian. When he reached one (Harry could tell because Poliakoff yelled it and then took off), Harry jumped into the wind current directly above their heads and lifted his arms to keep himself balanced.

They raced furiously, each leaping and ducking from one current to the next when they veered too far off course. Harry ended up winning by a mile, and tilted the front of his broom up to balance on the tail while he waited for Poliakoff to catch up.

"It is because you are so tiny," Poliakoff told him when he finally made it to their designated end point. "The wind does not catch you like it catches me."

Harry chose to ignore this slight and grinned instead. "Tell yourself whatever you need to," he said. "Want to try again?"

Poliakoff agreed, and they raced again. Harry won again. When Poliakoff reached the end point, he dove down a few metres above the treetops and waited for Harry to join him. "One more try," he said, panting slightly. "We can race to that tree out there." He pointed.

Harry shifted his weight and looked out at the tree Poliakoff was indicating. It was one of the taller evergreens in the forest, and quite a distance away. As Harry watched, a gust of wind buffeted the tree. A fleck of snow landed on Harry's glasses, and he frowned, suddenly uneasy.

"How far are we, anyway?"

"Not very far," Poliakoff said dismissively. "We go further all the time. Do you want to race?"

Another, larger snowflake landed on his other eyeglass, obscuring his vision. He balanced himself carefully as he reached up and cleaned it off. He didn't want to race if the weather was going to betray them. "It's starting to snow. We've got to be nearly as far as Hogsmeade."

"We are still on the grounds," Poliakoff said, and pointed. "Hogwarts is right there, see?"

Harry looked at the castle in the distance, then back at Poliakoff. He raised a sceptical eyebrow. "It's much further away than that tree. Let's race back instead. Then we can go inside and warm up."

Poliakoff followed as Harry started flying toward the castle, though he looked annoyed. "We will do this, then." He sighed. "Englishmen."

Harry laughed at him incredulously. "It's snowing! I can't feel my face. You have to admit it's cold now."

"I admit you think it is cold," Poliakoff corrected, slowing down and lowering himself carefully back into a sitting position. Harry imitated him.

"Let's race to Hogwarts," Harry suggested, and when Poliakoff nodded, Harry sped off on his Firebolt. He really wanted to get out of this weather.

As Harry neared the castle, a snowy owl detached itself from the owlrey and flew toward him. He landed near the front steps and held out his arm for her, taking the letter. Poliakoff landed nearby and waited as Harry thanked Whitey and watched her fly away again.

Harry smiled when he recognised Sirius' handwriting on the scroll. "I'll see you around, Poliakoff," Harry said. "I've got to read this."

Harry tore open the scroll as Poliakoff said his goodbyes and started walking back toward the Durmstrang ship.

Harry,

It was good to hear from you again, as usual. Remus says hello, as usual…

Harry grinned. Most letters from Sirius started off along these lines. He stepped inside as he read, because it really was cold outside. He leaned against the wall in the Entrance Hall, reading through Sirius' responses to what Harry had said in his last letter, and made a note of some of the hints about the Maurader's Map. His smile started to fade, however, when he realised he'd mentioned Draco, and that Sirius responded.

…I obviously don't have all the information, but I think your friend Hermione may have a point…

Harry frowned outright as he continued reading. Sirius confirmed that Lucius Malfoy had been tried, but got off by pleading Imperius. He sounded somewhat sceptical of the truth value in that, though it was the next few lines that really caught Harry's attention.

…I don't know very much about Lucius, we only ever met in passing. But I remember when we were younger, Narcissa was very talented at convincing my aunt (her mother) that she'd done nothing wrong, even with the evidence right in front of Aunt Druella's eyes. She usually got me in trouble, in fact. It doesn't surprise me that she'd marry someone with the same talent. She could convince Uncle Cygnus that me or Andromeda or Bellatrix had been at fault, even if we weren't in the house at the time. Of course, Bellatrix made it easy for her. She always had a quick temper, even before Azkaban…

Sirius continued in his reminiscing for a few more paragraphs, which wasn't unusual, then asked about school and the Tournament and how Harry was faring without Quidditch. Harry continued reading to the end, then went back to those paragraphs that talked about Draco's family. He hadn't know Sirius was related to the Malfoys.

It seemed like everyone had something to say about Draco's father, though, and none of it was good. No one thought Harry's ex-friendship with Draco was advisable. Harry folded up the letter, stuck it in his pocket, and left the Entrance Hall. All things considered, it didn't matter anyway. Draco had already made the decision for them both.

Harry soon found himself at the doors of the library without having meant to end up there. He went inside, and immediately spotted Anthony at his usual seat.

"Thanks for attacking me earlier in class," Anthony said when Harry sat down. "You know, we weren't actually partners. You were supposed to be aiming for Pansy."

Harry grinned, inexplicably cheered by Anthony's sour expression. "You got me."

Anthony shook his head. "I didn't know it was you. And it was supposed to be a mild stinging hex, Harry."

"I'm sorry," Harry said unrepentantly. Anthony never struck up conversation first. Harry considered it a huge step for him, even if he was just annoyed. "I was in a bad mood."

"You seem fine now." Anthony picked up his book again, which he had set down when he saw Harry coming. "What did you do to her, anyway?"

Harry sighed. "I refused an interview."

Anthony nodded. "You probably shouldn't do that in the future," he suggested. "Though if you'd like to discuss the Dark Arts, you know, just to actually have done it, I found this book."

Harry stared flatly at him.

"It's not actually about how to do any Dark Arts," Anthony continued, unperturbed. "It's about the ethical quandaries and justifications for using various Dark spells and curses. It's really fascinating. I should have looked into this before. Did you know the ancient Greecian wizards used to use Petrification to create statues? They would tell a Muggle they were just going to use them as a model, set them up perfectly, and then petrify them with a basilisk or a lock of gorgon's hair."

Anthony continued telling Harry about the book, and the various case studies and example scenarios it contained and so on. Harry sighed and listened dutifully. It was interesting, at least the parts when Anthony remembered his audience and deigned to tell Harry something he'd actually understand.

Harry glanced around during a lecture on the blood-boiling curse and it's controversial role in the wizarding culinary world, and realised the library was empty.

"It's dinner time," Harry interrupted. "Now let's go before you put me off my shepherd's pie any more than you already have."

"Fair enough," Anthony said, and Harry waited while he gathered his books. "But did you know Healers sometimes use pain curses locally to stimulate dead nerve endings? Licensed Healers are just about the only wizards not totally banned from using Dark Arts, and…"