AN: Must read "The Last" before reading this or you will be confused. I promise. This follows directly after that story and both follow "Worse than Death". Although WtD is not necessary to understand this particular fic, they are all part of my fan-fiction universe and future stories will reference them.

Best Kept Secret

Chapter One

Yumiko Kaze

Sokka had been right. Appa's unexpected calving had indeed slowed down their trip to the South Pole. The group had been forced to request another few weeks at the Fire Nation's Palace in order to wait for the calves to learn to walk and fly. Zuko of course had been happy to oblige; though some suspected he regretted the mess the calves were making of his courtyard.

Appa and the babies had been moved to a nearby meadow, which Aang, Sokka, and Katara visited on a daily basis. The babies had not grown much larger, they were still about the size of two penguin-seals, and all but one had quickly learned the art of flying from their mother. Aang had spent many happy hours chasing, racing, and wrestling with the entire litter.

When it was determined that their new mission could not wait any longer on account of the new additions, there was no choice but to bring the calves with. They were too young to leave their mother just yet, and leaving Appa and traveling by ship was out of the question. They were already behind schedule.

As it turned out, air bison were a lot like chicken-opossum. When the calves got too tired to fly by themselves, they simply crawled right onto Appa's back and rested in the saddle. At the time, continuing on their journey in this way seemed like the way to go.

Unfortunately, the extra weight meant Appa had to stop more. The stops were frequently made longer by the calves need to nurse, and of course to allow them to play around a bit in order to keep them from becoming restless during the flights.

At the moment though, the calves and Aang were fast asleep in a pile at the back of the saddle, thanks to an extra rough play session a few hours before.

Katara watched the entire pile rise and fall with the calves' deep breathing. "Aang looks so happy, doesn't he, Sokka?" She smiled. "I mean, can you imagine what Aang must be going through? The loss of his people, his home, all his old friends. Appa was really the only link Aang had to that culture until Mo-Mo came along. And even then…" she trailed off. "These calves are more than just Appa's babies. They're the hope for the rebirth of at least part of the air bending world."

Sokka looked thoughtful as he digested Katara's words—or possibly contemplating what to have for lunch. Sometimes it was hard to tell. "That's all well and good, but have you even thought about the future of the Avatar?"

She frowned. "Aangs future? He'll be a great leader. And I'm sure he'll bring a long lasting peace to our world."

Sokka tried to resist the urge to roll his eyes, "Yeah. I know. That's not what I meant. I was talking about the Avatar cycle. Remember that temple where the past Avatar's statues were all lined up from air to water, water to earth, earth to fire and then back to air?"

"Well yeah."

"So what happens after this cycle is completed?" Sokka rubbed his chin with a hand and stared hard at Aang's sleeping form across the way.

"What do you mean?" Katara felt her breath hitch and for the first time since the end of the war she felt real fear. She had been scared when they had thought Appa was dying, but that fear had nothing on the feeling that was beginning to curl in the pit of her stomach.

"I mean, Aang is an air bender. The next Avatar will be a water bender. Then earth and then fire again like Avatar Roku. What happens after that? The other air benders are all gone. Will the Avatar cycle just stop because there are no more air benders?"

"That's a good question, Sokka." Katara could feel that curl in her stomach twisting. She had never thought of that. "I don't know." What would the world do without an Avatar? For good?

Sokka continued his musings. "Or will it just skip air and go from fire to water?"

"Let's hope. Because even if there is peace now, without an Avatar we can't guarantee it will continue." Katara hugged her knees and stared past Aang and into the blue sky. "In fact, it sounds like guaranteed chaos."

Soberly, Sokka reminded her, "Even with an Avatar, it didn't last."

Sighing, Katara hung her head. Each Avatar had had their own battles to fight and mission in life. Kyoshi had fought Chin the Conqueror and Roku had Battled Sozin. "You have a point."

Aang tried very hard to keep his breathing slow and even. He had woken up not long before Sokka and Katara's conversation and had been enjoying watching Katara without her knowledge when Sokka had brought up what was turning into a most unpleasant topic.

What would happen once the Avatar cycle returned to air? Aang was too young to be seriously thinking about children, but even if he had several children and they each had several children, the air nomad blood line would get very thin very quickly. And if he and Katara had children? They would be either water benders or air benders. Not all of them would be able to pass on air bending. Or maybe they would be able to bend both? As far as Aang knew the Avatar was the only person capable of mastering all four elements. Did that mean it was possible for benders to learn to bend an element other than the one they were born too? If someone was born from parents of two nations could they have an affinity for both? He'd never heard of anyone who could bend more than one. By all known history, it wasn't possible.

I wonder, Aang mused. In the spirit state I closed Ozai and Azula's fire chakra… would it be possible to open a second bending chakra in someone? Or to give a non-bender the power to bend by opening a particular chakra?

Aang shook his head, turning away from Sokka and Katara in such a way that it looked as though he were merely turning in his sleep. Something told him that giving into those ideas might cause more harm than good. Then again, the first benders had been taught bending not by other benders, but by creatures like dragons, badger-moles, and air bison. Who was to say that helping create a new line of air-benders wouldn't be such a bad idea?

Eyes half closed, Aang watched the passing countryside idly as he mulled those thoughts around in his head. He sighed and rubbed his eyes; he was getting a headache.

And then he was distracted in the way that only a thirteen year old boy can be.

"Circus!"