Last Time ...

He cleared his throat and gazed out at the assembled students.

'Slytherin house will fight with us.'

That was then, this is now:

I breathed out in relief. I had hoped that was what he would say, and after Luna had backed us up it had seemed almost certain, but it was a relief that it was final.

Harry turned to me, and I was struck by the intensity of his eyes, as all the while, that lightning-bolt scar blazed against his forehead, drawing the eyes in the room towards us.

'You will be held responsible for any Slytherins who harm another Hogwarts student. And you will be responsible for their deaths, just as I am responsible for my house, and Luna for hers,' here Luna nodded, looking serious. 'If I discover that one of you has betrayed us and caused the death of any other student, it will be on your head; you will be the one who takes their punishment. I hope you are truly as sure of your housemates as you make out, as I hear that the death toll in Azkabhan lately has been rather high. Remember that as you fight.'

He turned sharply and strode off, back to his expectant followers. Luna took my hand gently.

'Don't mind him. This probably isn't easy for him; what with He-Who-Shall-Not-Be-Named and Snape both coming from Slytherin, I'm not sure he'll ever be able to truly accept you. Don't take it personally though.'

I smiled thankfully at her.

'I'll try not to. Thank you for your help, but I best get back to my house now. They'll be wondering what's going on.'

She nodded and followed Harry's path. I, however, took a different one, till I stood at the head of Slytherin house. A hush fell over them as they looked up at me expectantly, waiting for all of this to be explained. I was suddenly struck with a bout of nervousness. I couldn't talk to all these people! I couldn't tell them what to do! I was only a fifth year, for heaven's sake. This should be the job of one of the prefects!

I almost laughed at myself, though it wouldn't really have been situation appropriate. I could talk to two of the most famous people in the school without batting an eyelid, and yet I couldn't stand in front of the people I had grown up with and speak.

Perhaps it was because with Harry and Luna I knew that they were already judging me, had spent their whole life judging me. Whereas the people in this house were those whose opinions weighed heavily upon my decision making, and I was unsure of how to begin. I cleared my throat as I gazed nervously down at them.

'Uh- hello Slytherin house. Yeah, we're fighting … as you already know from what Harry Potter just said … um I hope that's all right with you, but if you don't, which I understand, because, ah, I know that some people have parents, and, um, siblings who might fight for Voldemort, then we won't think any less of you. Just – just find somewhere safe until the fighting is over … yeah …'

Not exactly a rousing speech, but it seemed to be all that was needed. Slytherin house began to cheer, slapping one another on the backs and laughing. A few people came up to me and shook my hand, saying things along the line of 'Well done,' and 'Thank you so much for this, it means a lot.'

It was all sort of overwhelming.

The sense of friendly camaraderie was instantaneously shattered by a bolt of red light that shot through the already broken window and hit a Hufflepuff girl in the chest. As she fell to the ground, screaming and writhing in pain, more spells began to fly at us from every angle.

McGonagall instantly became a flurry of motion, urging students into hallways, yelling orders at the teachers. The other houses began to move, but Slytherin was still milling around aimlessly until I realised that I was meant to direct them. Swiftly, I ran for the doorway into the more enclosed corridors, yelling for everyone to follow me. At the doorway I paused, waiting until the last person was through.

In the hallway it was chaos. We were safe from the spells in here, but the noises still echoed throughout the building, as the houses cowered together. I turned to the assembled Slytherins.

'Those of you that don't wish to fight, go now! The rest of you, stay together and make sure no one gets hurt. I need to go check where we're defending, I'll be back with instructions in a minute!'

I dashed off to where I could see the slightly-set-apart clump that was Dumbledore's Army, running up to the first person I saw, who just happened to be Neville, I grabbed his arm. He turned to me, startled, and I rapid-fire shot my questions at him.

'Where are we defending? Are we working with any teachers? What do we do if our ranks are broken through? Is there a signal we can send? Do you know what exactly we're up against? Is there any specific strategies we can use?'

He looked slightly stunned.

'Uh, what were those questions again?' he asked.

I repeated them, slower this time, and he gave me my answers.

'Slytherin will be defending the back of the castle. If your ranks are broken through send a green flare up into the sky. We're up against He-Who-Shall-Not-Be-Named. Also dementors and werewolves. Try to have small groups, with at least one person in the group knowing the patronus spell. That's … that's it, I think.'

'Thank you.' I told him, patting his arm and running back to where my house waited.