It would be a lie to say the library wasn't fun. That it didn't get his mind off things. Aida hated to admit it, but Father was right. He just couldn't be that sad when he was surrounded by scrolls, by the familiar smell of old paper, by the works of delightfully brilliant men.

It was a horrible day, the worst Aida had had in a long time, but it was still a wonderful time to be alive! In what other age would he be able to learn of bat-pigeons? That for their population to explode they needed three things found only in the Southern Archipelagoes: bugs, caves, and a lack of predators. They lived in large groups, and produced hundreds of thousands of tons of fertilizer every year, that was processed and shipped to the rest of the world. Indeed these humble bat-pigeons provided the backbone of modern day civilization.

It was cool. Fun. A neat little fact. But Aida didn't have to settle. No, this little delve into bat-pigeons opened the doors to a broader more interesting subject. What made bat-pigeon poo such good fertilizer? Why couldn't human fecal matter be a replacement? The great thing about the library was that such questions could be answered easily. All he needed was another scroll.

Aida slid out of his seat, and skipped to the non fiction shelf. He ticked his fingers past several scrolls, until he found just the study he was looking for. Fertilizer: A Crop's Scat. On his way back to his table he heard a muffled sob. A big burly man sat by himself, head buried against the table, romantic scrolls scattered about.

Aida gasped and bowed. "Prince Iroh."

"Ah Aida," Prince Iroh said, eyes wet and red. "Thank you for your recommendation. I was able to find Kojiro and bring his invention to Ozai. My brother's health is finally improving."

"You honor me my Prince," said Aida. "If ever you need my help you need only ask."

"I will keep that in mind," said the Prince sharply. The big man returned to his scrolls leaving Aida to his pursuit of poo.

But Aida found he couldn't focus. He'd look up and see the big Prince staring intensely at his scroll. Not rolling it one way or another. Just glaring at a single sentence, burning it into his mind. Aida tried to focus more on his scrolls, on how most fertilizers were composed of Nitrogen, Phosphorus, and Potassium. How chemical processes had recently been discovered to isolate Phosphorus and Potassium from common compounds found in soil everywhere in the world. On how Iroh was sobbing again. No not quite sobbing. Muffled whimpers more like. How was such a thing possible?

Perhaps it was because today was the Fire Nation Ball. Perhaps the Prince had been heartbroken. But if so, why was he surrounding himself with romance books. Wouldn't the Fire Lord have told the young Prince to pursuit a passion, as Aida's Father had? Science was not Iroh's passion, of that Aida was sure, but why not go through some firebending katas? Perhaps a game of Pai Sho with the little brother he seemed so fond of? Why wasn't Iroh with friends? Unless…

But no it couldn't be. Prince Iroh was nothing like himself. He was the greatest firebender the world had ever seen, the scion to its most powerful nation, he had nothing in common with a dyer's son from the Earth Kingdom.

"Why aren't you at the Ball?" Aida finally asked.

Iroh glared. "Why aren't you?"

"Because…" For some reason Aida found that he couldn't answer. He didn't want Iroh to know it was because nobody wanted to go with him. "I am an Air Nomad." Aida said confidently. "This is a celebration for the Fire Nation people. It's not my place to participate."

"I see." Iroh blinked and rubbed his eyes. "You got turned down too?"

Aida balked, and tried to answer. Unfortunately his tongue refused to form coherent sentences.

A small smile found its way onto Iroh's lips. The large man flopped out of his chair, swaggered over to a large map of the world draped over an entire corner of the library, and ripped it down. He spread it across the floor and motioned Aida to come over. He flipped a dozen golden coins onto the Southern Archipelagos, twenty seven silver coins, and a few bronze ones.

"Gold is steel Fire Nation ships, Silver is the Earth Kingdom's wooden warships, and bronze is Water Tribe Canoes," said Iroh cheerfully. "We've got to find a way to win."

"Ships are made of wood," said Aida. "Just burn 'em."

"Ah yes," said Iroh. "I've not explained the problem. It's not the Earth Kingdom ships, it's the three bronze coins. They've got waterbenders and they're near impossible to beat in the open seas."

"Why?"

"They're faster than us. They can clog our engines with seaweed and scurry away before we can react."

Aida frowned. Unlikely. Impossible. Aw yes that must be it. Iroh must have meant that the waterbenders were clogging the motors. Likely the propeller. "Couldn't you just build the boats with sails?"

"Not a bad idea, but they'd be an easy target for archers. They'd be to easy to burn down. What we need is something more maneuverable."

Aida sat down. "A smaller ship then?" He already had several ideas in his head. But the problem with a more individualized boat was that coal, the Fire Nation's primary energy source, was spectacularly inefficient. A single ship required hundreds of pounds of coal to power its engines. Fine for freight; not so good for what he had in mind. "Something small and fast, that can be deployed from a Fire Nation Battleship?"

"Yes," Iroh said. "If we could give chase to those waterbenders we could crush them like bugs."

"An internal combustion engine," said Aida. "And a liquid powersource. Some kinda oil most likely. But lion-turtle oil is rare. Hard to find. Need something more common."

Iroh squinted. "This has been a problem for years. Our best scientists have come up with nothing, and you're telling me-"

"Best scientists?" Aida asked. "I thought my old Instructor was still teaching at that dingy old school I used to go to." Aida shook his head. Iroh was many things but an evaluator of scientists he was not. If the royal doctors couldn't diagnose a simple case of asthma well… "What I'm telling you is…"

Aida closed his mouth and started drawing. The key would be the power source. The jets in his little boat would require a lot of power to work correctly.

"So small? Is it really possible?" Iroh frowned. "I don't think a wheel would be a good way of controlling these beasts. Very few soldiers have actually steered a boat before, and we don't have time to train them. We need something more intuitive. Something they can just pick up and use."

Aida nodded, and replaced the steering wheel with a pair of handlebars. Everyone had ridden a bicycle before.

"And this will really work?" Iroh asked, picking up the drawing.

"If you get an internal combustion engine, and an oil of some kind, your firebenders will be dancing around the water like they're on a pair of skis."

"Father will be pleased." Iroh rolled up the drawing. "You can expect a big reward for your contributions to the war effort."

Aida shook his head. "Don't tell him it was me."

"Why?"

"You know why." Gray eyes met gold.

"Yes." Iroh sighed, and turned to leave the library. "But Aida. The Fire Nation will be different when I rule. There will be a place for you. I promise you that as your Prince."

"I'm not Fire Nation," Aida said. "That was made clear to me today. You're not my Prince."

Iroh chuckled. "As a friend then."

Aida nodded. "I'm counting on it Iroh."