Author's note: The letters follow the events in "A Friend in Need: Part 1" while the narration continues Piro's account after "Have You Seen Him?"

Please let me know what you think as well as any constructive criticism.

Katara,

Humans are not welcome in my library. I will not allow the knowledge contained therein to be exploited by selfish humans, such as yourself, again.

I find your goal, while laudable, misguided. I find your offer, while substantial, inadequate.

No.

Wan Shi Tong

Fire Lady Azula,

I begrudgingly accept your terms.

The Knowledge Seeker that delivers this message is my liaison in the physical realm until your task is completed. Merely request the tomes you seek and, if they reside within my library, my agent will retrieve them for you.

Upon completion of the task, you will surrender payment to it immediately regardless of the outcome. The Knowledge Seeker shall not be followed or impeded in any manner by you or any of your agents. Failure to comply with my requirements will be met with swift punitive action.

Wan Shi Tong

I looked down at the unconscious forms of Katara and Sokka on the stone floor. They'd collapsed just inside the threshold to Aang's room with their arms outstretched. Beyond them, Aang's room was pitch black with the bold exception of a dull blue glow. The glow pulsed slowly from its point of origin at the center of the room. I breathed a sigh of relief: everything was exactly as I'd left it.

I shut the door and, one after the other, I carried Sokka and Katara outside to the fresh, open air. Your father's Flying Bison, Appa, plodded over to inspect them. A winged lemur peered out from the saddle and chittered at me.

"They're alright," I explained in a soothing voice as I braced myself, "They'll be right as rain once they wake up. Your rider is safe inside, too. I know he'll be glad to see you." I spoke mostly to myself. At the time I didn't realize Appa understood human speech. Do all Flying Bison? I really should look that up one of these days.

Below my institute, the fog held as thick as ever. From my vantage point, it looked as if alive. It rolled and swirled, billowed in some places while contracting in others. It breathed and and stretched out tendrils almost in an exploratory fashion. I could swear it searched the whole of its domain for some lost prey.

"Hey-hey, stop it, Appa! I'm awake! I'm awake!" Katara called out. I glanced back to see the flying bison turn its attention to Sokka. Appa's great red tongue licked him ferociously. No one could stay unconscious for long against that onslaught. I smiled for the first time all day. It didn't last long.

From closer to the gates of Taku it had any right to, I heard a loud thump and a crimson light pierced the fog bank and soared high in the sky: a signal flare. Other flares soon joined the first. The fog underneath took on a bloody quality. Fire Nation reinforcements neared, silent as the grave. I didn't know if my institute was their destination, but I had no interest in finding out.

"They're after Aang, aren't they?" Katara said from behind me. So rude, these young ones.

"Your airbender friend? I believe they became acquainted with each other shortly after he left my institute last night." I said. I went to say more, but only a gasp escaped my throat. Down far below, the fog gathered underneath the flares. At first I thought my eyes played tricks on me. It happens more than I care to admit. Yet, there it was: from all across the valley currents of fog formed. I don't know how else to describe it. It was like a streams merging to form rivers. Or an ant colony on the move. The fog surged and swarmed.

"What happened before? I was looking around and then… I - did we faint?"

I don't think Katara saw what I saw. I'm not even sure I saw what I saw. Gouts of flame? Smoke? Could the soldiers be under attack? By fog?

"Something like that," I managed to tear my gaze away and look Katara in the eyes - those cool, determined eyes. "Your friend, Aang you said? He's stable for now, but he isn't long for this world as he is now." I beckoned her to follow me into the institute. Sokka, too. Poor boy - he was covered head to toe in flying bison slobber and looked dazed. "I will need both of your help to move him."

Inside, Miyuki merely blinked at us with her jade eyes from her perch atop the dried herbs cabinet.

"Aang can't die." Katara held firm, "He's the Avatar. He's going to fix everything."

"Then we will need to get him to a powerful healer and soon." I stopped them outside his door. I dipped small towels in a cold water basin and set about the task of putting them on. "You'll need to tie these around your head to cover your nose and mouths before you enter. Don't take them off until we're outside in the fresh air. They'll protect you." Katara put it on without question, but Sokka looked dubious at my offering.

"From what?" Sokka asked.

I tied the towel around my head before answering. "From one of the most potent sedatives in my arsenal. So put it on, unless of course you enjoy a bathing in flying bison spittle."

The blue glow in Aang's room greeted us. I followed them inside before I shut the door. On the far wall, bathed in the light of a glowing mushroom, Aang slept peacefully.

"What is that?" Sokka asked with wonder at the mushroom.

"Lactarius illumine. It's found mostly hanging from the ceilings of underground caves. When fruiting it emits a chemical that incapacitates any creature in the vicinity. Water inactivates the chemical while fire halts the fruiting process entirely. In a pinch it makes for an excellent, fast acting sedative."

While Sokka stood mesmerized, Katara seemed to only have eyes for Aang.

"What's wrong with him?" She asked. She caressed his head tenderly.

I pointed to his left leg. The bandage was nearly soaked. I'd need to replace it soon enough.

"Embedded deep in his femur is a serrated arrowhead. I've tried, but I can't remove it. I'm not physically strong enough. It wounds him further each time he moves that leg. I could only put him to sleep in hopes help would arrive."

Between the three of us, it didn't take us long to carry him to the flying bison. What a sorrowful moan it made when it saw Aang - broke my heart. Before we left, I knelt down in front of Miyuki and asked her to hold down the fort for a few days. Little did I know it would be closer to a few months. I still don't think she's forgiven me.

"Will your cat be OK while you're gone?" Sokka asked.

"Miyuki knows how to handle herself. She's wanted by the Fire Nation, y'know." I waved to my beloved Miyuki as we lifted off. She merely licked her chops.

"Uh huh."