The interior of the Dark Lord's tower was almost familiar to him by now. Voldemort always kept it dimmed, but as a tactic to disconcert him it was fairly ineffective. A habitual insomniac, Sev was no stranger to wandering the corridors of Hogwarts in darkness.

"Lord Voldemort," he said, with a respectful nod.

"Ah, Snape. We thought perhaps you weren't coming." The Death Eater leader was sitting in a chair in the corner, legs propped casually up on a small table.

"I followed the same procedure as before," Sev said, but not over-defensively. Voldemort wasn't attacking him, only studying his reactions - much as he would be doing, if the situation had been reversed.

It was strange, but in front of the one person he most needed to fool, he could allow the most of his true personality to shine through. At the school he guarded his intelligence, put on the emotions that he knew would be expected of him. With Voldemort, he could let all that drop and show the cool calculation underneath.

"And what if I had required your presence immediately?" asked the Death Eater leader, in the same deceptively light and airy tone.

Sev looked pointedly at where the Dark Mark was no doubt still burning black under his sleeve. "If you had required my presence immediately, I've no doubt I would have known about it."

Voldemort laughed, not a cackle or a crazy giggle, but a low, earthy sound of amusement.

"Indeed! Now," he leaned forward, resting his chin on his fist, "tell me of this Foe-Glass."

"It's a Ministry device; I assume you've heard what it's designed to do?"

"Yes." Voldemort smiled slightly. "But what does it actually do?" It was the same question Sev himself would have asked.

"Oh, it does its job... to a certain extent. It's hard for me to study it fully, without a better class of enemy."

"You think you don't have enemies?"

"I think they don't know they're my enemies," Sev countered. The older man nodded in acknowledgement, but immediately challenged him again.

"You've had months to study the device; are these all the conclusions you've drawn?"

"The device is not all I've been studying."

Voldemort smiled again. Sev was passing the tests he was setting up. "Tell me."

"The shield around it is an exceptionally well-designed system." He could say that with full certainty, having developed it himself. "It can't be bypassed or removed by force, but that doesn't mean it can't be overcome."

"How?"

"The shield-spell has an element that means that even if you use the correct code, it registers who passed through it-"

"So if it the device goes missing, they'll know who took it." Voldemort nodded. "This can be circumvented?"

"I've figured out how to shut that element down for a short time," he agreed. To be precise, he'd invented the system in such a way that it was possible to do that. "However, you'd still need the code to get in."

"We have the code."

It was just as well Snape didn't have Malfoy's uncontrollable need to smirk when his plan worked perfectly.

This had been the most dangerous edge of the bluff; if Voldemort had asked him to give over his own code, subtly different from the ones Dumbledore had handed out to his staff, all would had been lost. However, Sev had staked everything on his ability to read personalities - and been right. Voldemort responded to Sev's intelligence by making himself seem to be one step ahead all the time - he wanted to make it clear that everything Snape was reporting, he already knew.

The first phase had gone perfectly - but this was no time to relax.

"You tell us that the best time to make a move would be this 'summer festival'; why?"

"The list of reasons Malfoy gave you, cloaked as his own reasoning."

Voldemort laughed. "Quite! And was it his own?"

"Why yes, of course. Once I had told him the conclusion, he was quick to figure out how to realise it."

Voldemort laughed again, but his face abruptly hardened. "Why are you here, Snape?"

This time, Sev knew, the answer wasn't 'because you summoned me'. "I go wherever advantages me most," he said carefully.

"Of course. And what happens when our little organisation ceases to be... the most advantageous place for you to be?"

It was a very fine line indeed between truth, lies, and saying the wrong thing. Sev chose to brazen it out with a flicker of Slytherin arrogance. "Perhaps it's best that you see that doesn't happen."

"Perhaps it is," said the Death Eater leader, with an unreadable smile. "I notice you don't leap to assure me your loyalty is without question," he added lazily.

"Nobody's loyalty without question."

Voldemort nodded slowly, then broke into soft chuckle. "I like you, Snape. You think like me."

"I know."

"Very well." He stood up, suddenly. "We will bow to your superior judgement." There was just enough of an edge of humour in his voice to hint that he didn't quite mean it but he wasn't mocking Sev either. "My Death Eater will retrieve the glass on the day you suggested. And you, I trust, will make sure this can happen."

"I will." That was no lie. He fully intended to let the Death Eater agent get away with it - he just planned to find out who they were while they were doing it.

Voldemort nodded and abruptly dismissed him. "You may go."

Sev went.

Malfoy was lying awake when Sev returned to their dorm. "You've been out," he observed neutrally.

"I was summoned." Sev slid back his sleeve to display the Dark Mark, slowly beginning to fade from black to its original red.

"Summoned for what?" Malfoy demanded. Being the only one in the know might be one of his greatest pleasures, but he didn't much like being on the other side of it.

"They wanted to interrogate me about the Foe-Glass."

"They've had our reports." By which Malfoy meant his reports. He was obviously not happy with the idea of Sev's word being taken over his own. Sev trod carefully.

"Our lord likes to hear these things for himself."

"And?"

"He liked your idea of staging the raid at the festival. He commanded me to weaken the magical shields for him." Deliberately cosying up to Malfoy would be far too obvious, but a few carefully chosen words could emphasise Snape's 'subordinate' position. If Malfoy chose to take it that way - which, of course, he did.

"And what are we to do?" asked Malfoy sharply.

"He didn't entrust me with your orders." Again, he subtly pointed out Malfoy's more trusted position. "But I should imagine a few little... distractions couldn't hurt."

Malfoy grinned slowly. The thought of magical nastiness always put him in a better mood. "Hmm, yes. I suppose I could... try to think of some suitable targets."

"Somebody heavily involved in the festivities, perhaps?" suggested Sev with a raised eyebrow. Malfoy smiled back. They were both well aware that James Potter had managed to wriggle his way into being involved with just about every event on the programme.

"Yes..." said Malfoy slowly. "We'll just have to see what we can do to improve the entertainments. After all," he smirked, "we can't let it be said that house Slytherin didn't get into the spirit of things."

As the summer rolled on, the entire school was overtaken by a buzz of excitement over the upcoming festival. There was to be a mini-Quidditch tournament, three matches in quick succession, and a host of unofficial betting circles had sprung up. The duelling club was to put on an exhibition - theoretically, it would be set up involve no actual injuries, but that wasn't likely to last very long. There were bets on that too, including on whether Potter and Malfoy would get the chance to go head to head, or if the teachers would be smart enough to put a stop to that before it happened.

Professor Alomanicia would be reading fortunes, and Hagrid was beside himself over the weird and wonderful creatures that were going to be on display. The seventh year Muggle Studies class were putting on a Muggle play, albeit with a few magical twists.

Rumours abounded that Professors Malachite and Vitae would be taking part in the duelling themselves, sparking a rash of inter-house scuffles over who would be the winner. Neither of them would confirm or deny the rumour, leading to even more speculation.

The hum of excitement infected all the lessons. Sev suspected that even as Dumbledore had set this festival up for a purpose, he had also wanted it to be exactly what it seemed - a way brighten up the year for students and staff alike. The mutterings of dark events far and near had all but died out in favour of more enjoyable speculation.

The end of year exams came and went; half the students failed because they were unable to concentrate, but the teachers didn't even seem to mind. They had been afforded even more of a glimpse of the troubled times than their students, and were just as eager for the chance to escape for a day.

Dumbledore summoned the eight ex-Prefects to him a few days before the big event.

"First of all, may I congratulate you all on your hard work in making this day the great success it is sure to be. This project stands as a tribute to how much we can achieve when we all pull together."

Sev was less impressed by the flowery praise than he was by Dumbledore's ability to talk of cooperation with a straight face. In all the meetings they had attended, this one no exception, the Gryffindor and Slytherin delegations had glared each other into oblivion.

Lily, of course, knew that Sev's hostility was only an act - but she could act too, and her dislike of Narcissa certainly wasn't feigned. Narcissa Salenica treated all her inferiors - which, in her mind, worked out to everybody - with the kind of icy disdain reserved for something you'd stepped in. That definitely rubbed Lily up the wrong way; it seemed to grate with her even more than Malfoy's outright cruelty. Sev had heard her say that Narcissa reminded her entirely too much of her big sister.

Narcissa and Malfoy were certainly a match made in a special kind of hell. Sev felt a vague sense of pity for their potential offspring - any child those two produced didn't have much of a chance of turning out with anything that passed for a normal personality.

Not that he himself could ever be accused of that, but at least he wasn't actively homicidal. His logic might make him unemotional in many regards, but it stripped away the bad as much as it did the good. Sev wasn't entirely immune to human emotion, he just knew better than to be guided by it - something a hothead like James Potter could never understand.

Lily was as bad. She had been the first to know the true extent of his mission, and understood the stakes involved - but she seemed unable to accept his logical weighing up of pros and cons as a way to reach decisions. Hers was a value system of doing 'the right thing' even when 'the right thing' would kill you and everyone you wanted to help, and something a little morally questionable would save you all with minimal cost.

Sev, naturally, found it rather hard to see the logic in that.

Lily was smart enough not to interfere in what he did, but she seemed to have appointed herself his part-time external conscience. And, irritatingly, she was perceptive enough to guess when there was something in the air.

Now, for instance, she kept shooting him suspicious glances across the room. He kept his face as impassive as came naturally, but she knew that proved nothing. As Dumbledore talked, she mouthed 'what?' at him. He gave her a look that he knew she would be able to translate as 'I can't believe you're stupid enough to try and communicate with me in a room full of people'.

She responded by sticking her tongue out. He fixed a lazily indifferent look into place, and turned back to Dumbledore. No doubt Lily would be sticking to him like glue on the night of the festival. Well, he could always distract her with Malfoy's torment of James if he really needed to get rid of her.

Professor Dumbledore was wrapping up his big motivational speech. "And finally, I need a volunteer-" James's hand was already up. Dumbledore smiled fondly at him. "Somebody who's a little less overinvolved, I think," he added kindly.

James looked good-naturedly disappointed. It had become almost a running joke that the festival was going to be pretty much the James Potter show, as he scurried from Quidditch to duelling to the play to a few dozen other activities. The Slytherins, of course, had sniffed and called this yet more proof of the way the whole system was prejudiced in favour of Gryffindors. At exactly the same time as they stated loudly how pathetic it all was and none of them would want to be involved.

Dumbledore's eyes swept around the semi-circle of sixth years and fell - purely by 'chance', of course - on Snape. "Ah, Severus. You're not too busy on the day of the festival, are you?"

"No, Professor." James snickered into his hands.

"Who'd want him?" he said in a stage whisper.

Dumbledore was an expert at not noticing such things. "If you don't mind, Severus, I'd like you to act as a liaison between the members of staff; make sure everything keeps running smoothly."

"Yes, Professor," he nodded. The headmaster had rather neatly handed him a licence to lurk around the staff without engendering suspicion.

However, before he was home free, Lily had a card to play. She pulled a vaguely disappointed face. "I could have done that," she said to James, in a stage whisper of her own. Dumbledore proved mysteriously able to hear this one when he hadn't picked the other.

"Then so you shall. You don't mind a little company, do you, Severus?"

The assembled sixth years choked in disbelief, and James Potter made a sound of disgust. "Aw, Lily, now look what you've done!"

Lily just shrugged. "Ah, don't worry about it." She leaned closer to James. "He gives me any trouble, I'll just push him in the lake."

"Don't do that, you'll poison the monsters." James glared across at Snape. Sev sneered right back. Now he was going to have the fun of executing his flawless plan with snide commentary from Lily every step of the way. Strangely enough, the prospect wasn't all that distressing.