Author's note: Since the first chapter of this fic ends on a literal cliffhanger (har har), and since I've gotten more inspiration about what happens next, I've decided to continue this story, which will most likely be three chapters in total.
Chapter 2: Pulse
Katara crouched into the salty spray at the bow of her umiak, the sail behind her pulled taut. The wind was her companion and her whip, urging on her boat even faster as she bent the waves to her will.
"I'll write to you every day," Aang had promised her.
She smiled at him. "Your letters will be the brightest part of my day."
Her hand clutched a wad of paper that had turned stiff and dry after being splashed with salt water—and blood. Aang's blood.
Aang's blood, which scrawled out a single word: HELP
Katara took his hand. She traced his fingers, imagining that when he held a brush to write to her, carefully balancing the slender handle between his forefinger and thumb, he was really holding her.
"What are you doing?" he had asked.
"Just trying to remember what your hand feels like," she had said. She gave him a teasing grin. "So the next time we hold hands, I'll know it's really you."
Katara supposed the blood on the tattered invitation could belong to anyone. Momo had borne the message, landing in the snow at her feet earlier that morning, chittering and agitated. But someone else besides Aang could have sent the winged lemur—Zuko or an Air Acolyte or one of the Royal Guard.
But she knew the blood was Aang's. She had healed enough of his wounds, pressed her hand over his flesh as crimson life oozed between her fingers, to know that the blood was his. She knew his blood like the timbre of his voice or the lift of air in his steps. Perhaps she could tell that it was his blood because she was a waterbender and a healer.
Or, perhaps, because she was a bloodbender.
She pushed the thought away with a shudder.
"After the sun goes down, look up at the sky," Aang had told her.
"Why? What's so special about the sky?"
"It's going to be a full moon in a few days." He gently grasped her hand, the one that was tracing his fingers. "The moon will be full of light," he had said, clasping their fingers together, "just like I'll be full of thoughts about you."
The round face of the moon shone down on the dark surface of the South Sea. The Patola mountains reached up into the sky like clusters of ragged teeth. Katara couldn't get any closer to the island mountain range without being dashed against the rocks.
She sailed into a small cove surrounded by steep, rocky walls. Instead of looking for a place to tie her boat, she froze the water to keep the boat from drifting away. Then she pulled out a wooden bison whistle from her tunic, pursed her lips around the mouthpiece, and blew.
But instead of snuggling closer to Aang, Katara bit her lip.
"What's wrong?" he had asked, his eyebrows furrowing with concern.
"I've never been away from you during a full moon. Not since—since—"
"Not since Hama?" Aang had said, finishing her sentence quietly.
A hulking shadow burst out of the low clouds that wreathed the mountains. The shadow grew closer and larger, and Katara's heart leaped at the sight of curved horns and a massive tail.
Appa landed near the boat, the sheet of ice groaning under his weight. Katara clambered up his furry side and into the saddle, with Momo close behind. She hopped onto the sky bison's head and grasped the reins that dangled from his horns. Relief coursed through her veins.
In the glare of the full moon, she could feel other veins around her, too—the blood of her friends.
Katara nodded, a jerky movement of her head. "Yeah. Not since…Hama," she had said, speaking the old bloodbender's name in a low whisper.
Aang ran his hands up and down her arms, then pulled her close. "Think about it this way. The moon spirit is Yue, and Yue is our friend. Besides, we'll both be looking at the same moon—together." He smiled. "Even though we'll be apart, looking at the moon will bring us together again."
Katara held the reins, but she let Appa take them to the Southern Air Temple. They hovered within the shadows of the peaks as blue spires rose before them, the walls of the ruined temple washed white in moonlight. Among the towers and mountain ridges and rocky crags, Aang was nothing more than a speck. Invisible.
She was never going to find him.
As despair froze her heart, the blood of Appa and Momo called to her. Sang to her. Invited her.
Take a look, their blood seemed to murmur. Reach inside us. Feel our veins pulse in your hands. Sink your fingers into—
Katara gripped the reins hard. Her fingernails bit into her palm. She forced herself to think about something else.
She thought about Aang.
The moon will bring us together, he had told her.
"The moon will bring us together," she whispered to herself, trying to forget about her companions' blood and focus on Aang.
But the blood around her was so warm, so alive, so ready for her to—
"The moon will bring us together," she rasped harshly, as if hissing the words would drown out the blood rushing around her.
The spot where Katara sat on Appa's head was warm. Countless veins and arteries ran through the sky bison's body in a beautiful tangle. The strings of a puppet. All she had to do was lower her hands to his gentle head, reach inside, and—
"The moon will bring us together, the moon will bring us together," she said, repeating Aang's words in a frantic mantra. "The moon will bring us—"
Suddenly, she knew how to find Aang.
"I'll try to remember that," Katara had said. But even if the moon brought them together in spirit, she would still rather be with Aang the way she was now—wrapped within his arms.
"When the moon turns full, just remember—we'll be together again soon enough," he had reassured her.
Katara watched the sky. And she waited.
The edge of a large cloud drifted over the glowing disc of the moon.
As the moon shrank to a sliver and disappeared, she steered Appa closer to the Air Temple. They hung in the air as Appa slowly wove back and forth. The pitch-black night hid them from the enemy, but only for as long as the cloud covered the moon.
Katara had to find Aang. She didn't have much time.
"When you're finished with the pilgrimage, I can take a boat and meet you at the Air Temple," she had said.
Aang shook his head. "I'll come pick you up."
"But I want to see you as soon as I can."
Blinded by darkness, Katara suddenly saw in other ways. Through her nose, crisp mountain air stung her nostrils. Over her skin, brisk fingers of wind stole her warmth.
In her ears, the blood of her companions beat louder than ever. She shut her eyes—useless, she knew—and tried to tune them out.
"Sweetie, you're strong and capable and fierce, and I love that about you. But you don't have to sail to the Air Temple," Aang had said. He folded his arms around her back. "I'll come pick you up."
Katara sighed. Yes, Aang was the one with a sky bison, and he always picked her up. But she wanted to return the favor, for once. "You should let me come to you, sometimes," she had protested. "It's only fair."
Through the wind rushing in her ears, Katara listened. Through the maddening thrum of the blood around her, she listened. Through the stillness of the temple mountain, where nothing stirred, she listened.
She listened, until something did stir.
A flicker.
Just a leaf in the wind, she thought.
But then the flicker came again. And again. And again. A rhythm in time, thready and slow.
Katara gasped. Aang!
"I don't want you to go through all that trouble. And I want to pick you up." Aang leaned in until their noses touched. "Just wait for me, okay?" he had murmured.
"Okay. I will," Katara had replied, even as she hated the idea of being away from him for so long. "I'll wait for you."
From upon a ledge tucked into the mountainside, thick with moon peach trees, came the beat of Aang's blood.
Hope, impossible hope, surged in Katara's chest. It's Aang! He's alive!
But the swell of hope crashed into a flood of panic. His heart pulsed, barely there. A flame about to go out.
Katara snapped the reins and urged Appa forward with a brisk "Yip yip!" She raced against the cloud about to uncover the moon, against the life ebbing from Aang's body.
"Wait for me, Aang,"she said, her desperate whisper carried away by the wind. "Wait for me."
Author's note: This chapter was written for a prompt sent in on tumblr by sugarqueen_katara: "Wait for me, will you?"