A/N: I apologise hugely for the delay in posting this chapter! I did a little one-shot in between chapter 3 and this because I didn't have enough time to sit down for a few hours and do this justice; however it is finally done! I'm going away again this weekend but still hope to get chapter 5 up more promptly. Thank you to all my reviewers, sorry I haven't had time to reply to your reviews but they do mean a lot to me and I'm trying to take your suggestions into account so please keep them going! L x

As she marched along the corridors, Minerva felt full of adrenaline for the battle. Her earlier panic had evaporated; all traces of sleep, firewhiskey and shock had left her. She knew, deep down, that she had been waiting for this moment all year, and particularly all evening. And despite the near certainty that violence would ensue and lives would be lost, it felt good to finally be standing up for the school, which she felt she had let down this year.

Although all these thoughts were running through her head, Minerva McGonagall was not one to become distracted, and she listened carefully as they walked, checking that the only sounds she could her were her own movements and those of Harry and Luna behind her. And it was a good job she was – suddenly, she picked up the sound of a fourth pair of footsteps. She had a shrewd suspicion who it might be, but did not hesitate to raise her wand as she stopped dead in the corridor and asked, "who's there?"

"It is I."

Good, thought Minerva, I can get him out of the way now so that we can assemble our troops in peace. She eyed him carefully, noticing that he was not in his nightclothes – clearly he, too, had expected something to happen tonight.

"Where are the Carrows?"

She didn't want to answer this question, preferring instead the idea of cursing him on the spot, to get him back for the way he had treated the school the last year, for killing her best friend, for the way he had acted towards the Potters – she knew that he had called Lily a Mudblood while they were at school, she knew that he had led Voldemort to them and she knew how he had treated Harry for 6 years. Yet she maintained her composure, knowing that the moment to strike would present itself, and decided to feign ignorance.

"Wherever you told them to be, I expect, Severus."

She watched as his eyes searched the air around her, feeling rather satisfied at his discomfort and rather smug that Harry and Luna had managed to get into the school right under his nose.

"I was under the impression that Alecto had apprehended an intruder."

Continuing her pretence of not knowing anything about an intruder, Minerva carefully replied, "really? And what gave you that impression?"

She fought to keep back a derisive laugh as his left arm muscles seemed to spasm unconsciously and hoped that his Dark Mark was hurting him terribly. Feeling exhilarated that she could finally speak plainly to him, she did just that, her last two words dripping with sarcasm - "Oh but naturally, you Death Eaters have your own private means of communication. I forgot."

Minerva felt a grim satisfaction at his lack of reply to this, but it had not escaped her notice that he was still looking for Harry and that he was advancing, albeit very slowly, upon them. She had to be on her guard.

"I did not know it was your night to patrol the corridors, Minerva." He sneered. Minerva thought vaguely that if she had as little as a Knut for how often she'd wanted to wipe that sneer off his face she'd be able to crush him under all her riches. However, she forced herself to keep calm, and replied cautiously, not willing to start making up stories until she had to.

"You have some objection?"

"I wonder what could have brought you out of your bed at this late hour?" Minerva had to make a huge effort not to snort at this; she'd been out of bed at this hour catching students on night-time strolls, breaking up parties in the Gryffindor common room and generally patrolling more often than she'd been in bed at this time.

But she opted for the truth, or at least, some of it: "I thought I heard a disturbance."

"Really? But all seems calm."

Snape's eyes were boring into hers now; Minerva closed her mind to him, knowing what he was trying to do.

"Have you seen Harry Potter, Minerva? Because if you have, I must insist -"

She did not need to employ Occlumency this time; the moment had finally come to get rid of the slimy git, who was, quite frankly, wasting her time when she could be thinking up a battle plan and Harry could be off finding whatever it was he wanted to find.

Moving with the speed and agility of her Animagus form and completely ignoring the tiny, but still present, 70-year-old part of her that was grumbling 'I want to go back to bed', she slashed her wand through the air. But Snape wasn't an idiot, he was ready for her attack and she stumbled at his sudden Shield Charm. Not to be defeated, however, she turned her attention to the torches on the walls, and as she turned the flames of one of them into a huge ring of fire that made straight for Snape, she thought drily that fire was a good weapon to use against him, because he preferred the damp and the dark, rather like an Inferius or some Devil's Snare. She did feel a jolt of concern, however, as she hoped that Harry and Luna had had the sense to get out of the way.

Minerva had not duelled to this ferocity for a long time; although she had fought last summer, her opponents' skill had nowhere near matched hers, and they had been easy and quick to defeat. Snape had turned her fire into a gigantic snake, but Minerva barely had time to be scared of it; she swung up her wand arm fast and the next second it was just smoke, but she twirled her wand and each wisp of smoke became a dagger.

"oppugno!" She thought fiercely, flicking her wand at them; Minerva was not duelling to kill, exactly, but she wouldn't be bothered if Snape did die. She hadn't expected them to hit, he was too skilled for that, but she did allow herself a slight smirk as he had to hide behind a suit of armour like a child as the daggers flew at him.

"Minerva!" came a squeak from behind; she reeled round, knowing that it was Filius Flitwick but not willing to let her guard down. In spite of the situation she smiled slightly at the sight of her fellow Heads of House, her friends, racing down the corridor to come to her aid – even Horace Slughorn, whom she could not recall ever having seen run before.

"No!" Filius shouted in his high-pitched voice, his wand raised, "you'll do no more murder at Hogwarts!" He jabbed his wand at the suit of armour and Minerva watched with disappointment as Snape managed to escape it. He retaliated - however, it seemed to Minerva that he had realised he was outnumbered and was panicking slightly; the suit of armour did not hit them as he had intended, merely the wall a few feet away from them. In the split second they all watched it crash, Minerva noticed out of the corner of her eye a mass of black robes sprinting away - she ran full pelt after him, Filius and Pomona panting along beside her, but now he was jumping – he smashed through a window – for a moment she thought he might fall and finally get his come-uppance, but no – he flew like an overgrown bat towards the boundaries.

"Coward! COWARD!" Minerva heard herself screaming, as rage and frustration gushed up inside her. She had wanted to defeat him, to avenge Dumbledore, avenge her students – but he had gone, and it would be pointless to follow him; she needed to think of the school and the public enemy, rather than her private battle with her former colleague.

They stood around the window, breathing heavily, Minerva exercising most of her considerable amount of willpower to prevent herself from following Snape and concentrate on the task in hand. She heard running footsteps behind her and, despite her anger and worry, had to fight an urge to laugh as she realised that her colleagues did not know Harry and Luna were here – what a shock they were about to get!

The urge vanished as quickly as it had appeared, however, as she answered what she knew Harry was about to ask – "he jumped."

Filius and Pomona both shrieked at the sight of Harry but Minerva was watching him repeat her exact thought processes as he ran to the window, yelping "you mean he's dead?"

"No, he's not dead," she replied, unable to keep the bitterness out of her voice. "Unlike Dumbledore, he was carrying a wand… and he seems to have learned a few tricks from his master." She added with disgust. She had known Voldemort must have trusted Snape for him to have succeeded in being a double agent for so many years, but this just proved that Snape was as close to Voldemort as anyone could be.

Minerva turned away from the window as she heard the unmistakable sounds of Horace catching up in his unfit state, and watched with amusement as he tried to take in everything that was happening, spluttering, "Harry! My dear boy… what a surprise… Minerva, do please explain… Severus… what…?"

"Our headmaster is taking a short break," Minerva replied drily, pointing to the window. Bastard, she thought, cowardly, stinking – but her inner venting was interrupted by a yell from Harry. She looked at him in alarm; he was gripping his forehead and had gone very white.

"Professor, we've got the barricade the school, he's coming now!"

She did not ask how he knew this; clearly Dumbledore's plan for him to learn Occlumency had failed, though she couldn't help but think that the connection seemed to be proving very useful this evening.

"Very well."

Minerva turned to her colleagues, her head clear and her blood pounding.

"He Who Must Not Be Named is coming," she informed them, ignoring their reactions. "Potter has work to do in the castle on Dumbledore's orders. We need to put in place every protection of which we are capable, while Potter does what he needs to do."

"You realise, of course, that nothing we do will be able to keep out You-Know-Who indefinitely?" Filius pointed out squeakily. Minerva opened her mouth to reply but was cut off by Pomona – "but we can hold him up."

"Thank you, Pomona," Minerva said, sharing a look with her and knowing they were both thinking the same thing – each would protect Hogwarts and its students until their dying breath, if they had to.

"I suggest we establish basic protection around the place, then gather our students and meet in the Great Hall. Most must be evacuated, though if any of those who are over-age wish to stay and fight, I think they ought to be given the chance." Minerva knew that efficiency was key to this battle, and fortunately, it was something she was very good at.

"Agreed. I shall meet you in the Great Hall in twenty minutes with my house," Pomona said, and Minerva felt a rush of affection for her friend as she saw that she was already hurrying to the door, muttering the names of plants that would be useful in battle and keen to get going with her role in the castle and students' protection.

As Filius began casting charms out of the window, Minerva saw Harry go up to talk to him and took the opportunity to have a think about what was ahead. She knew that she had to let those who were of age fight, but it was not what she wanted – if she had her way, they would all be going back to their families and staying out of the action. She was particularly worried about her Gryffindors; partly because they were her house but also because being the boldest students, they tended to take the most risks. However, they were, she reminded herself, perfectly capable of looking after themselves and had the right to fight for the triumph of good over evil. She told herself sternly that she must channel her efforts into the battle ahead – not spend the whole thing running around checking on students. Meanwhile, a battle plan needed to be established.

Shaking herself out of her thoughts, Minerva called to Filius that they would meet him and the Ravenclaws in the Great Hall and beckoned Harry and Luna to come with her. She needed to play her part in the protection and then send them off to the Great Hall to meet everyone else.

However, she was delayed by Horace, who was blustering about how dangerous it all was. She didn't have time for this; there was protection to be sorted out and a battle plan to decide, and so she replied sharply,

"I shall expect you and the Slytherins in the Great Hall in twenty minutes, also. If you wish to leave with your students, we shall not stop you. But if any of you attempt to sabotage our resistance, or take up arms against us within this castle, then, Horace, we duel to kill."

"Minerva!" he gasped, but she didn't care. She wasn't going to have anyone stand in her way; this battle needed to be fought and won, and she was proud to be in charge of the Hogwartians.

Her nostrils were flared as she replied, "the time has come for Slytherin house to decide upon its loyalties. Go and wake your students, Horace."

It was as if she were making up for lost time; all the frustration and powerlessness she had been feeling over the year were vanishing as quickly as if they were objects she could Vanish with her wand. Minerva McGonagall was a born leader and as she finally took control as she had wanted to all year, she was even more formidable than usual. She felt more alive than she had done for a long time as the adrenaline pumped through her and her mind was filled with ideas for how to fight the Death Eaters.

Now, however, she needed to summon up all her concentration for a spell she had never used, and had hoped she would never need to use. Although it was her first go, she was sure it would work; she had confidence in her own abilities, knowing she was a powerful witch without being arrogant about it.

She stopped in the middle of the corridor and raised her wand high, focusing her mind on what she wanted to happen – "piertotum – oh, for heaven's sake, Filch, not now -"

Minerva knew she was being sharp with him but, really, what a moment to interrupt her at!

"Students out of bed!" he was half-wheezing, half-shouting, "students in the corridors!"

It would have been funny were it not for the little time they had and the importance that she performed this spell.

"They're supposed to be, you blithering idiot! Now go and do something constructive! Find Peeves!"

This idea had just struck her upon seeing Filch; she remembered how Peeves had resisted Umbridge and knew that, despite his maddening attitude and incessant pranks, his loyalty lay with Hogwarts. He could be very helpful in this battle if he wanted to be, which she was sure he would – Peeves was not one to miss out on the action.

"P – Peeves?" Filch was stuttering. Minerva resisted the urge to roll her eyes.

"Yes, Peeves, you fool, Peeves! Haven't you been complaining about him for a quarter of a century? Go and fetch him, at once!"

Filch went grudgingly, muttering under his breath, but Minerva had already turned her attention back to the task in hand.

"And now," she cried impressively, "piertotum locomotor!"

It worked at once; every suit of armour and statue in the castle came to life, adding huge numbers to the army at her command.

"Hogwarts is threatened! Man the boundaries, protect us, do your duty to our school!" she spurred them on and they followed her instructions; issuing war cries they shuffled and marched downstairs towards the doors as fast as they could.

"Now, Potter, you and Miss Lovegood had better return to your friends and bring them to the Great Hall – I shall rouse the other Gryffindors."

Minerva headed to Gryffindor tower as fast as she could, thinking wryly that she had another battle to fight before the real one – her underage Gryffindors would not take kindly to being sent home. She decided not to tell them, yet, that some would be allowed to stay while others had to leave – time was running out to get to the Great Hall and she didn't want them holding her up with protestations; she might as well deal with theirs and any from the other houses at the same time.

Upon entering the common room, she roused the Prefects first and hurriedly explained to them what was happening. If they felt any shock, fear or excitement they did not show it but did as she asked them straight away, going round the other dormitories waking up the rest of the house. She waited in the common room, grateful to the Prefects for their reaction and proud of the students under her care.

They stumbled down the stairs, some rubbing bleary eyes, others looking wide awake and eager to know what was going on.

"Please follow me to the Great Hall," Minerva said, surveying them all with beady eyes to check that everyone was there, "He Who Must Not Be Named is about to invade the school, and we need to ensure your safety before we fight."

She glanced around the room again, noticing that although many of the older years seemed to be steeling themselves, a lot of the younger ones looked nothing short of terrified.

"Don't worry," she added gently, "as long as you follow my instructions, you will be evacuated quickly and safely. I'm not going to let any of you be harmed. Is that clear?"

She almost smiled as she noted the surprised and confused looks on some of their faces; although she was very fond of her students, it was rare for her to openly display this kind of protectiveness. A few people nodded.

"Good. In that case, off we go."