A/N

I went with the literal meaning because I figured fewer people would and, thus, it would be more original. However, I may have gotten both meanings in this story. You'll just have to read and see (:

*Chordae Tendinae (heartstrings): Cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart; the tendons and nerves that brace the heart.

~.~.~.~

Azula's eyes narrowed and she glanced to her left. There she was. Just standing there: defenseless.

Zuko prepared himself to receive his sister's blast of lightning. He paused, realizing she wasn't looking at him.

With a smirk, Azula's arm shot out; electricity crackled through the air around her. She pointed two fingers at the girl.

Zuko's eyes followed her arm and he turned. Without thinking, he ran. Three steps, but the lightning was too high. He jumped. "No!" He shouted, not Katara. He couldn't lose Katara.

Katara stared, horrorstruck, as Zuko's body sailed through the air, taking the deadly blast that was meant for her. Her eyes were wide with fear—not for herself, but for Zuko. She couldn't lose Zuko.

Zuko crashed to the floor, the force of the bolt causing him to skid several feet. He laid there, curled up, the electricity coursing through his body. He twitched in agony from the current that was too strong, too powerful, too deadly. He threw his body open to allow the energy to run free.

"Zuko!" Katara shouted, running towards him. A blast of lightning struck the ground in front of her. She could hear Azula's maniacal laughter. She turned, ready to face Azula, when she heard a faint groan.

Katara! Zuko couldn't leave her to defeat Azula on her own. He couldn't let anything happen to Katara. He rolled onto his stomach and struggled to lift himself up.

Katara turned. Zuko! He was alive. She ran towards him, desperate to heal him, to save him. Azula shot a second flame of blue at her. Waterbending saved her hand, and she jumped out of the way just in time to miss a third attack.

Zuko made a fist and raised his hand, attempting to firebend. He need to protect Katara.

A fourth blast of electricity knocked Katara off her feet and she rolled forward to avoid getting hit.

Using her lightning, Azula flew to the roof. "I'd really rather our family physician look after little Zuzu, if you don't mind." She fired at Katara again with lightning.

Katara ran to safety behind the pillars, closely followed by Azula's blue shots of fire. She stood up, determined to fight to the end, for Zuko's sake.

"Zuzu, you don't look so good," Azula called to her brother who remained motionless on the ground.

Katara peeked out from behind the pillar at Zuko, only to be seen and shot at by Azula. She took off, using the pillars to protect herself.

Azula jumped from the roof as Katara ran.

Katara paused behind a pillar. She steeled herself and jumped out, bending the water in a nearby trough and pulling it towards her, around the pillar, and shooting it to the roof. The tiles from the roof exploded and the water crashed to the ground. Where was Azula? Katara stood up in disbelief.

Azula used her lightning to fly from the roof and landed behind Katara.

Hearing Azula, Katara glanced behind her at the deranged fire lord* before taking off towards the trough. Katara bent the water into sheets of ice, sliding along it get away from Azula.

Azula chased after Katara, shooting a battery of blue flames at the water tribe peasant.

Katara skated around toward another building, but stumbled when she ran out of water. She rolled onto a grate that covered palace's water line. Water. Looking up, she spotted a chain. She got an idea.

Azula walked around the pillars to where Katara had fallen. "There you are, filthy peasant," Azula snarled, as Katara jumped from behind a pillar holding the chain.

Katara stood her ground as Azula walked toward her.

Both women glared at one another.

Katara lashed four thin water whips at Azula.

Azula dodged the whips and flipped across the grate, closer to Katara.

Katara stepped onto the grate.

Azula spread her arms out, aiming two fingers at Katara.

Katara jumped back, bending the water beneath the grate up around them and freezing it.

Time itself froze. Katara, both arms raised, was suspended by the ice. Azula, ready in a lightning-bending stance, looked down, up, and then at Katara.

Katara's eyes were wide with fear, yet she remained calm. Thawing only the water around her, she placed the chain around Azula's right wrist. Katara thawed Azula's arm to pull it behind her. Moving through the water, Katara tied the chain around Azula's other wrist, and then secured them both behind Azula's back. Katara pulled Azula down and tied the rest of the chain to the grate. Then she dropped the water. Both women panted and coughed before Katara stood up and tightened the chain.

Azula grunted and tugged against the chains, but she was captured.

Katara left Azula and sprinted to Zuko.

Zuko could hear someone coming and he struggled to get up. He had to make sure Katara was okay.

Katara ran to Zuko's side and gently turned him onto his back. She covered her hand with water and placed it on his chest, above his heart, where the lightning had struck him. The water glowed as it healed what the lightning had destroyed.

Zuko grimaced in pain.

Katara could feel the damage under her hands. The top of his liver had been torn, as well as the diaphragm. His heart, though, had received the brunt of the blow. As she healed it, she realized it was a miracle he was still alive. The tricuspid valves had been severed from the chordae tendinae. Without these heartstrings, his heart should have failed.

Zuko opened his eyes. He could feel that his body had been mended.

At Zuko's response, Katara lifted her gaze. Her face brightened into a relieved smile when she saw that her healing had worked.

"Thank you, Katara," Zuko whispered.

Katara could hear the echoes of his pain in his words. Tears gathered in her eyes as she remembered that this had happened because of her. Because he had saved her. "I think I'm the one who should be thanking you," she replied softly as the tears glistened and ran down her face.

Zuko tried to get up, but he was still too weak.

Katara wrapped an arm around Zuko's back to help ease him up. She pursed her lips in worry.

Zuko looked up at Katara above him. He could tell she was still scared for him and blamed herself for his injury. As she helped him up, he raised his face up towards her. He brought his hand up to her neck and pulled her closer, lightly touching his lips to hers.

Katara started, but then gave into the kiss.

The taste of salt mixed with her sweet breath. With his thumb, Zuko brushed away her tears. "It's going to be okay, Tara," he mumbled against her lips.

Azula's screams erupted through the night, breaking the moment.

Katara helped Zuko to his feet.

Azula writhed like an animal and fire shot from her mouth.

Zuko stood, Katara's hand on his back, and looked down at his older sister. Tears streamed down her face as she collapsed, panting and crying out in anguish. His face was stony; a cold mask.

Katara stared at Azula, shocked. Then she turned her face away in sorrow for the tortured fire princess. She looked up at Zuko, worried about how he would handle seeing his sister like that. But she couldn't read anything in his hard expression. All she could do was feel the heat emanating off his body and feel his papillary muscle and chordae tendinae contract as his heart beat.

~.~.~.~

A/N

So the last line is kind of cheesy. I do have an another version that doesn't include the literal meaning of heartstrings. Please, please review!
Zutara forever

~ Krystynn