98 th day of our journey and the 23 rd at the Northern Water Tribe. Today, black snow fell out of the sky. It heralded the arrival of a huge fleet of Fire Nation ships. The water tribe warriors and other city dignitaries were called to the Ice Hall where Chief Arnook gave a solemn speech, saying many will vanish from the tribe in the upcoming battle. Then he selected some warriors for a dangerous mission. My brother volunteered.

Everyone scrambled to get ready for battle, and soon warriors were lining the huge city walls. We sighted the Fire Navy ships at noon and they attacked without even an attempt at parley. Not that we were expecting it. Huge fireballs were flung off the decks of the ships straight at the outer city walls, damaging them by the sheer force of impact. Thankfully, walls and buildings here are made of ice, so the risk of fire spreading is less than in other cities. The Avatar launched an attack on several ships, single-handedly disabling them, but there are hundreds more…

They bombarded the outer walls solidly for hours, but the waterbenders have managed to stave off most of the damage, and, as yet, there are no fatalities among us, though casualties are many.

The Fire Nation called off their attack at dusk, but they will probably resume tomorrow at daybreak. It is going to be a sleepless night.

I was in the Sparring Circle when it happened. I had just beaten all the other guys Master Pakku had trained, and received some rare words of praise from the old Master himself. None of the boys wanted a re-match. If that was a test he had set me, then I suppose I passed with flying colours.

It was an entirely different matter with Aang. He was playing with Momo, completely oblivious to what was going on. His distractedness and fooling around reached new heights today, but I had already resolved to speak to him as soon as lesson was over. If he was acting up like this because of me, then he'd have to quit doing it. It was his duty, as Avatar, to learn.

Master Pakku then told Aang to step into the sparring circle and take the place the other guys had refused to.

Aang had to fight me!

That made me a bit uncomfortable. I didn't want to do it. It was one thing practising moves with Aang, but an outright match was not something I thought I'd have to do. As Pakku said, his raw talent was not enough, but I'd've felt bad whether I won, or lost, a match against Aang.

On the other hand, I knew there'd have to be a first time for everything, so, with a deep breath, I took my position in the Sparring Circle.

Aang's mind was on other things however, and, to my dismay, he showed Master Pakku his Snowman trick instead.

We were both unimpressed.

'Oh right, Sparring Circle! Hang on – I'll make a sparring circle!' and he started rolling in a circle, bending the snow deep into the ice in a round shape, goaded on by the chuckling of some of the other guys.

I was seriously thinking of bending some snow right over him and freezing him to the spot, when I noticed the black snow falling.

Black snow.

I remember it falling back at the Southern Water tribe like it was yesterday. It heralded the Fire Nation raid on our village. I was a little girl then and didn't know what the soot meant, and how the coming of the black snow would change my life forever.

But now, when I saw the dancing black specks falling out of the sky, I had a heart-stopping sense of déjà-vu that rooted me to the spot. Everyone around me was looking up in bewilderment at the darkening sky.

'It's the Fire Nation!' I choked out.

Master Pakku's head whirled round to look at me.

'They're coming!' I whispered, as the pure white snow turned a polluted black at my feet.

Seconds later it dawned on me that we must have led them here. The North Pole hadn't been attacked in decades! It couldn't be a coincidence – not after the battle at the Northern Air Temple. They had found us! The soot came from the chimneys of Fire Navy ships – probably Admiral Zhao's fleet.

Just then the sound of a gong rent the air: the reverberating, deep rhythm was urgent and fast.

Master Pakku took off at the sound of it.

'Maybe we should follow him,' Aang said, the levity of a few moments completely disappearing. 'You know what this means, don't you?'

'The Fire Nation found us,' I replied, bleakly.

He nodded miserably. 'They're after me. It's like Kyoshi all over again.'

'Kyoshi was a small village on a small island. This is the North Pole, Aang: it has stood proud and undefeated for all of the 100 years of this war! And it'll do so again: we're not running away this time!'

'Yeah, we'll beat them like we did at the Northern Air Temple!' Aang replied, brightening, 'you're right, Katara'.

We went inside the Great Ceremonial Ice Hall where all the warriors were gathered and sat at the back, where we were soon joined by Sokka, who had a distraught look on his face. He did not speak to us, but kept his eyes on the raised dais up front where Chief Arnook stood in ceremonial dress with Princess Yue by his side. The chief called upon the Ocean and Moon Spirits to be with us as he feared many would vanish forever in the upcoming battle.

He called it 'battle for our existence' and given what had happened to the Air Nomads and even the Southern Water Tribe, I knew his ominous words were not an exaggeration. A deep-seated dread shivered through me, as I tried to push away the memories of the devastating Fire Nation attacks on our village. This big city was not a small tribal village, and it was well-equipped for war, with massive defensive structures and an army of well-trained water-benders and warriors. Still, Chief Arnooks' sombre words about the coming death of many of the faces around me was terrifying. They were so young…

So many faces had disappeared from the Southern Water Tribe too, and they had been just as young. My mother had been a young woman… and many nameless others all across the whole world.

All because of the Fire Nation greed and cruelty.

Perhaps this was the time of reckoning. Perhaps this was the time to avenge what happened to the Southern Water Tribe. And what could be more appropriate than our sister tribe in the North Pole? Now that I was a trained waterbender, I counted for something, and there was Aang with us, too.

It was then that Sokka volunteered for a dangerous mission for Chief Arnook. I was fearful, but also, in equal measure, proud of my brother. I saw him glance at Yue as he went up to get his warrior's mark from Chief Arnook, but I don't think he did it to impress her, judging by the sad, distraught look on both their faces.

Later, I joined Aang and Chief Arnook outside the building. Aang was looking at the distant ocean beyond the city walls. The streets were deserted, as all women, children and the old and infirm had been instructed to seek shelter in the deep ice caverns beneath the city, so, although the sun was shining brightly, there was an unnatural silence over the city. The black snow had stopped falling: whether because it had stopped snowing or the ships had stopped moving, I couldn't tell. I squinted hard at the horizon, but could see nothing. The sun is always low on the horizon in this tundra winter, but the visibility was crystal clear now that it had stopped snowing.

'The stillness before battle is unbearable,' Chief Arnook was telling Aang 'Such a quiet dread.'

'I wasn't there when the Fire Nation attacked my people. I'm gonna make a difference this time,' Aang said, with fierce determination.

'I'm grateful and honoured for your help in the upcoming battle, Avatar,' Chief Arnook gave a small bow.

'It's the least I could do. I'm ... I'm sorry your people had to go through this, Chief Arnook. The Fire Nation is here because of me,' Aang confessed guiltily.

'Of course it is. We knew this would happen.'

'You – you did?'

'Yes. Ever since the Spirit light glowed, some months ago, and indicated that the Avatar had returned. The tribal elders told me then that the Avatar would seek the waterbending knowledge of the Northern Water Tribe one day.'

'Oh.'

'I just didn't expect it to be so soon, but I knew that when it did, it would give the Fire Nation every reason to attack us again and remove, with one blow, the only remaining undefeated Water Tribe, as well as the only threat to the Fire Nations' continued expansion: the Avatar.'

'And yet you welcomed us when we arrived,' Aang said humbly, 'Even though you knew what was coming.'

Chief Arnook looked at Aang, his craggy, weather-beaten face serious.

'Yes, Avatar: you are the only hope that balance can be restored. And believe me, after a 100 years, that hope had almost gone. So we knew when you came, that we'd have to do whatever it takes to help you. Besides, this Fire Nation attack would have come anyway one day: if the last cities in the Earth Kingdom fall, then they would inevitably turn their attention to us.'

'I will make sure you will not be disappointed to have me on your side, Chief Arnook,' Aang spoke with quiet determination, 'I'll get Appa now.'

'Katara,' Chief Arnook turned to me, 'You should take your position with the warriors on the outer ice wall. That is where you will be needed most.'

'Yes, Chief Arnook.'

My heart swelled with pride at the Chief's quiet acknowledgement of my skills as a warrior, and I ran to take my place on the outermost ramparts of the ice wall. I knew that I was going to do my best to make both Chief Arnook and Master Pakku proud of what they had allowed me to learn, despite the deep-seated prejudices of their tribe.

Aang came up on Appa, and Sokka appeared by my side. The whole wall was lined with determined-looking Water Tribe warriors, some in war paint and some marked for battle by Chief Arnook. Finally, at around noon, a lone Fire Nation ship appeared on the horizon. We all tensed as a tiny fiery speck left its deck and hurtled towards us.

It looked ridiculously tiny and innocuous at that distance, but that impression was swiftly dispelled as it came closer and we saw what a huge fireball it was. It impacted with the outermost wall with a loud, hissing noise, as ice turned to steam, followed by a thunderous sound as the wall cracked and split in all directions.

The second Fireball fell in the canal and the third hit the wall we were standing on sending ice shards and snow in all directions. I was buried under a huge pile of snow, but I could hear the muffled shouts form the other warriors and Appa roaring. Before I could bend it away, I heard Aang goading Appa into the air.

Sokka helped me to my feet and I caught a glimpse of Aang heading out towards the ocean and the on-coming fireballs. He deflected one but the other one struck the wall again. Soon I lost sight of him for I got busy rebuilding the collapsed wall and refreezing it .

Other fireballs were coming our way and I joined the waterbenders in raising great waves of water and ice to neutralise their destructiveness before they could reach the walls or houses. The stench of the burning oil from the fireballs soon hung over the whole outer wall, for although we stopped many of them, encasing their polluting, burning, filth in ice, many more kept appearing. I couldn't see Aang in the distance, but the first Fire Nation ship had a smoking deck and was encased in sharp, jagged ice. Northern Water tribe boats were heading out to sea, where more Fire Nation ships had appeared.

There was no time to see what Aang was doing. I had my hands full trying to fix the damage to the ice walls of the outer ramparts or block the fireballs from getting through our defences. The bombardment slowly but steadily increased, and the acrid fumes of whatever the Fire Nation ammunition is doused in before launching, hung low over walls and city. Many of the Fireballs reached far over the defensive walls and landed within the city precincts, causing havoc to its delicate architecture. Had the city been made of other than ice and snow, it would long ago have been set aflame. Still, the fireballs fell so fast and furious that by late afternoon we realised the outer wall would soon be damaged beyond repair. Some of the waterbenders there were overwhelmed by the sheer number of fireballs coming their way.

Their screams are still ringing in my ears.

Sangok, one of Pakku's better students, was one of them. I saw him go down in a hail of burning black stuff from one of the four fireballs directed at the wall where he stood, all of them arriving simultaneously. He managed to deflect and neutralise three of them but the last knocked him clean off the damaged bastion. He fell, together with part of the ice wall, in a tangle of burning black stuff and fiery detritus, shrieking in pain.

That's when Master Pakku gave the order to retreat to the inner wall. I was closest to Sangok, so I went down to where he had fallen and bended the ice and snow off him.

The smell of burning flesh hit me as soon as I uncovered him. It's a smell that's somehow more pervasive and strong than the foul oils used on the material of the fireball itself. A sickening smell, and one that suddenly, very forcefully and vividly, brought horrifying images to my mind. Our igloo had smelt like that. I had pushed the memory of it to the remotest regions of my mind many years ago, in order to be able to function and keep myself sane.

I couldn't let those memories resurface now. Not now.

Sangok was barely conscious, his face twisted in pain. The back of his head behind his left temple was burnt away, his left arm broken and the skin burnt black. The snow and ice had thankfully extinguished the fire burning his clothes. I gently bended some water around my hands and placed them on his injuries, as Yagoda had taught me, feeling the soothing coolness pass from my hands and onto the hot skin of his head and arm. I hoped it would limit the scarring.

His eyes fluttered open.

'You'll be ok!' I said, smiling reassuringly, as some of the other warriors came up, 'They'll take you somewhere safe.'

'Don't leave me!' Sangok's eyes were glazed and he winced as they lifted him up, so I don't think he knew what he was saying.

'It's ok, Katara. You go with him, and keep the Healing Water on his skin,' one of the other guys said, breathing heavily through his blue mouth gag, 'They're not sending so many fireballs over now, and we can handle them.'

So I accompanied Sangok to Yagoda's infirmary, where Yue was helping with the injured. The smell of burnt flesh was even stronger here.

'Good job, Katara' Yagoda said. 'He'll have some scarring, but I think we may just save his hand and arm functionality, so his waterbending won't be affected.'

Sangok had returned to a sudden lucidity. 'Glad to hear that,' he smiled, wearily 'Master Paku'll be pleased. Perhaps I can convince him I can take on something bigger than a sea sponge! Thanks, Katara'

'I would say you've taken on more than a Sea Sponge today, Sangok.'

Princess Yue was moving about the stricken warriors, a stack of bandages in her hands and a shocked look in her eyes.

'How is it going, Katara?' she asked, 'Yagoda and the other healers have their hands full here, and I'm trying to help in any way I can'.

'The outer wall is in ruins, but other than that... How - how many casualties are there?'

'Thank the Moon and Ocean Spirits, none of the warriors have lost their lives -' she paused, but I continued her sentence in my mind: - as yet.

'I think I should get back,' I mumbled. Both Aang and my brother were out there in that raging firestorm, and every second I wasted away from my post weighed heavily on my conscience.

'I'll come a little way with you,' Princess Yue said putting down the bandages, and following me to the door, 'Yagoda needs me, but to see them in so much pain... it's just so hard.'

She spoke with a quiver in her voice. I put my hand on her shoulder and squeezed it gently, because sometimes, there really are no words that one can say to lessen the anguish, and I understood what she was going through.

'Most of them will be fine, Yagoda's an excellent healer,' Yue said, 'But some of the waterbenders are so severely burnt that Yagoda thinks they may not fully recover their skills. Those men have the most desperate look in their eyes...'

'I once saw some earthbenders that had the look you describe, Yue. They had been tortured by their Fire Nation guards. And once, my hands were so badly burnt - I thought I'd end up like that too. That's when I discovered I had healing powers, and healed myself. However, I still remember that horrible feeling – like part of you is lost forever and you can never be the same again...'

We had arrived on a high terrace overlooking the city. The smouldering remains of the fireballs were sending black, snaking trails up into a fiery orange sunset and beyond the broken walls were fire nation ships arraigned in a long, menacing row.

'They've stopped firing!' Princess Yue looked at the distant ships, and our ears rang with the unnatural silence after the many hours of constant barrage and flames. Suddenly, I saw Appa's huge shape silhouetted against the inflamed sky. Aang was back!

'Aang!' I shouted and we ran off to greet him.

Thankfully, Aang was unhurt, but looked dejected. Appa was tired and flumped down as soon as he landed. Aang slid off and sat in a huddle at Appa's feet.

'I can't do it,' he said putting his hands to his head, 'I can't do it.'

'What happened?' I asked, alarmed.

'I must have taken out a dozen Fire Navy ships, but there's just too many of them. I can't fight them all!'

'But, you have to! You're the Avatar!' Princess Yue cried.

'I'm just one kid.'

Aang's voice was barely audible, and had a pleading, desperate note in it. He looked so small and alone as he buried his head in his arms that my heart went out to him. Princess Yue's words made me realise just how much pressure he was under. The people here really believed in him and expected he would make the difference he himself said he would. I knelt down by his side and put a comforting hand on his shoulders.

'If you took out twelve ships, Aang, then ... then... how many are there?' I dreaded to hear the answer, because I knew it would've taken a lot to discourage the young Airbender.

'Over 150,' came the muffled reply, and his shoulders sagged under my hand.

Princess Yue gave a gasp. 'So many?'

'We can only see sixteen of them from here. I never imagined there were so many more...' I glanced up at the distant horizon where the small black dots were lined up.

'Those must be the bombardment ships,' Princess Yue said, squinting at the horizon, 'I heard my father tell the elders that the first wave of ships would weaken our defences, and then the second wave would carry troops for the invasion.'

It was, well and truly, a siege.

'Aang did take out a lot of them,' I said in Aang's defence, 'As I'm sure the warrior ships did. I saw the smoke coming from the first few...'

'I aimed at putting their trebuchets out of order,' Aang said lifting up his head, 'that's their main weapon, and it worked for most of them, but some of those ships carried blasting jelly...'

His eyes sought mine and I was shocked at the haunted look in them.

'It was terrible, Katara,' he whispered, the gray eyes hazy with shock and pain.

I realised it was not just the desperation of facing an immense naval fleet that was bothering Aang: it was the crude realities of war.

'There were bodies everywhere, floating in the sea and on the burning decks... Those ships had no business carrying blasting jelly! Why did they have to carry basting jelly!?' His voice rose angrily in reaction to the painful recollection.

'It's not your fault, Aang.'

'Maybe it was! Maybe I should've found some other way! Maybe I should've -'

'That blasting jelly was meant to destroy my people,' Princess Yue interrupted suddenly, 'It was brought here with the intention of laying the city and the Northern Water Tribe to waste. If the consequences fell upon the perpetrators' own heads, then better that, than on the innocent heads of my people!'

'You're right, Yue, but the monks always taught me to respect all life, and I can't help feeling as though I'm responsible...'

'You didn't make them carry the blasting jelly, Aang,' I said 'You didn't make them hurl fireballs at us for four solid hours! This - this is war, Aang, and you missed the first 100 years of it, but for the rest of us, we've had to live with its consequences, and its presence, all our lives!'

I looked at him sadly, wondering how to explain to a twelve -year old monk who'd been brought up to respect all life, the harsh realities of war that have been part of our bedtime stories since when we were in swaddling clothes! Aang has only seen the consequences of the war for only a few months of his life, whereas we were brought up to them. Even in the only large scale battle we've been in, during the attack on the Northern Air Temple, the Fire Nation Army never got that close to us that we could witness any direct effect. The last devastating explosion that caused most of the casualties and finally set the Fire Nation soldiers fleeing, also blew away a good part of the mountainside, hiding the fatalities from sight. We had left the temple almost immediately afterwards.

'They are Fire Nation soldiers, Aang', I continued, more gently 'They all know what they're on a ship for, and have accepted the risk as well as its injustice! Just as you have accepted to risk your life to help save this Tribe. We all have.'

'Yeah, I guess you're right, Katara. Still, enemy or not, their screams for help sounded very... human. Some were picked up by the other ships, but for others it was too late. You just didn't see...' his voice trailed into silence as he was lost in the memory of what must have been a very rude wake-up call as to the grim nature of a battle.

'Come with me, there is something I need you to see,' Princess Yue said.

Aang airbended himself upright and followed her in silence as she led him towards the makeshift hospital. I waited outside in the gathering twilight, knowing full well what lay inside, and not wishing to smell brunt flesh again.

It was not long before they came out, and Aang looked both chastened and sickened.

'I know you have been differently brought up among the legendary Air Nomads,' Yue was saying, 'But in war, the difference between "us" and "them"; between 'victims' and 'enemy' becomes more defined and insurmountable. It is the difference between attack and defence, between a proud freedom and being conquered and enslaved. If what you say is true, and there are a 150 ships out there waiting to invade us, then you may very well be witnessing the end of the Northern Water Tribe. You cannot, as Avatar, let that happen...'

'I'll think of something, Yue' Aang said, unhappily.

'We'll help you, Aang, you know we will,' I said 'But we should all get a rest now, and meet up later. I wanna see if Sokka's ok, if Master Pakku needs anything, and then I'm going home for a bit. There's something I have to do... and I'll see you all here in a while.'

At the warrior's quarters, Master Pakku said the Fire Nation would probably start bombardment again at dawn and look-outs had been posted all along the shoreline. In case of any untoward activity, the gongs will sound. As for Sokka, I didn't get to see him, but one of the other warriors told me he'd been taken off Chief Arnook's mission. This is a bit worrying, though I'm secretly glad he's not on some suicide mission. Finally, in the dark, I headed towards home, knowing there was one last thing I had to do...

When I arrived, I took the scroll and hastily wrote down all of today's happenings. There isn't much space left now in my mother's scroll. I'm trying not to think of it as a bad omen, but with a fleet of ships bent on destroying this land and its people, I can't help but wonder if these are the last words I'm writing in the last few inches of space left in this scroll. When I finish, I will write Gran gran's name on it and where she lives, seal it, freeze it in a block of ice and hide it, so that if something should happen to me, I can hope that someday it may be found .

Aang, who had gone to stable Appa, has just come in and he's seen me writing hastily in the moonlight. He hasn't said anything, but I'm sure he knows it's a form of farewell letter. Many warriors do it before battle, and I guess, in a way, this is one. Only Gran Gran may unlock the scroll's hidden writing, but I'm not going to write any farewells. I still hope we can make it through all this, and if I'm the one who doesn't - well, I think I've said enough in the rest of this scroll for it to have served its purpose.

I am keeping my fingers crossed that I can fill the last few inches of this scroll with the record of a resounding victory over our enemies. With the Avatar on our side it cannot be otherwise.

I only hope I will be the one to record it.