Legend would have it that one hundred years ago, Fire Lord Sozin, leader of the Fire Nation, led his army against the Air Nomads. Under the comet that now bears Sozin's name, the Fire Nation's soldiers' power was multiplied hundredfold, and they killed the Air Nomads to the last man and woman – except for one. The Avatar, the reincarnation of all the previous Avatars, who held all four elements of the world in balance, survived.

The legends speak of a wise old sage with a wide-brimmed hat, a grey cloak and a staff, who wanders from town to town spreading cryptic advice and bringing justice to those who would upset the balance of the elements, capable of turning back entire armies with but a swing of his walking-stick.

And if you went back twenty years, those legends would speak of an ancient master of the arts, old but still muscular and charming, his face covered in a single yet aesthetically pleasing scar, who travelled between the Southern and the Northern Water Tribes on the back of a giant lion-turtle.

Another generation back would speak of a brave young warrior-general-monk skilled in the art of warfare, with whispered rumours that he had been seen attending the Earth Kingdom War Council, planning an attack to retake the Hu Xin from the Fire Nation.

In the trading-ports bordering Kyoshi Island, there was a persistent legend that the spirit of the great warrior-Avatar Kyoshi had personally become reincarnated as the Last Airbender, fighting a one-woman guerilla war against the Fire Nation while dressed in an impeccable and combat-worthy sari. The legends did never quite explain how Kyoshi, famed for her stealth in her era as well as the never legends, managed to avoid detection in an orange sari, but she was the Avatar, and one did not question the Avatar's greatness – especially not Kyoshi's greatness – anywhere where it might be heard by the elite stealth warriors that upheld her legacy.

And in some legends, the Last Airbender had died fighting off troops, sections, formations, divisions and even entire armies of Fire Nation soldiers, only to be reborn among the Northern Water Tribe, where he or she was trained by the best tacticians of the Three Free Kingdoms to lead a united army against the Fire Lord Ozai at some unspecified time in the future, best foretold through complex and time-consuming divination of tea leaves, the clouds and the intestines of a chicken or – if the lord and lady would be so kind – an ox, which would give the best reading.

One common element to all the legends though, was that the new Avatar had been the Last Airbender. Unfortunately, this was perhaps also the least true part of the legends, something that Prince Zuko of the Fire Nation had come to regard with a particular fierce loathing, even for a firebender.

Before Zuko sat the last of the Last Airbenders, a weak old man with weathered, furrowed and dark skin. He wore robes that might once have been white, but were now just a dusty gray. He was the fifty-first Last Airbender so far, and the third just this week. In fact, his uncle, General Iroh, had celebrated the oh-so-honourable occasion with leaves of his finest tea and a diverse sampling of the local quinine.

Not for the fifty Avatars you didn't catch, his uncle's words rang in his ears, but for that there are fifty fewer to search amongst. You must learn to look on the bright side of things, Prince Zuko.

Like all this food, which are made with fantastic spices, hard to get at home!

"I know you are the Avatar!" Zuko lied, and pointed at the man. "You are coming with me! "

"My father is not the Avatar, you barbarian thugs!" a younger man – though still older than Zuko – yelled at him. He was of no concern, pushed up against the wall of his own stone hut by Prince Zuko's armed guards. "He's not even an airbender, just a harmless sandbender, like all of us!"

"Is this true, old man?" Prince Zuko asked, staring intently at the bony patriarch.

The answer came in the form of a small whirwind of sand forming from the ground – these uncivilized people didn't even have floors – which quickly dissipated as the old man stopped shuffling his hands.

"See? My old and frail father is not an airbender, least of all some man from an old legend! Release us immediately!"

"Then if he is not an airbender," Zuko said, his voice booming, "he could not possibly stop this!"

Prince Zuko's arm shot towards the old man's face, already engulfed in flames. With the sheer force behind it, the young man could probably have shattered the old man's jaw – if not his face – but the move was a bluff, telegraphed well in advance and despite its speed, stopping far from the old man's face. The ball of fire, the spiritual energy of Zuko's breath made incarnate, would continue forwards, a powerful and deadly blow.

But it too would come to a stop mere thumb widths from the old man's face, singing a few hairs at most. At his uncle's behest, he had adopted illusions and trickery – coward's tricks, really – in favour of formal duels. It, at least, saved time and energy in these unpleasantly warm and dry parts of the Earth Kingdom's hegemony.

But the old man was quite safe; just as Zuko had known; a sudden gust of wind deflected the tiny fireball away from his toothless grin. Zuko's arm shot out and seized the old man's wrist, and in a single motion pulled him off the ground and into the waiting arms of Prince Zuko's personal guard.

The fifty-first Last Airbender had been arrested and was about to be taken onto Prince Zuko's barge. With any luck, the fifty-second Last Airbender was somewhere less warm.

But even if the true Last Airbender was at the bottom of a volcano covered in a lake of fire, Zuko would find him and bring him home as his tribute to his father, the Fire Lord Ozai.