Since they had recovered from the initial joyous shock of Asami having her face returned, Korra came to terms with the knowledge that she still had a job to do. As she looked at Koh's rapidly rotting corpse, her heart sank with the realization that what she did for him, she would have to do for the rest of the world. The Mother of Faces had inadvertently given her the impetus she needed to move on with her duties as the Avatar. Sympathy, mercy, sacrifice... those were traits of the Avatar. Those were traits that had neutralized the hatred inside Koh, and those were traits that would help Korra destroy the plague. She had only been able to stop him by being a vessel for his self-reflection, for his troubled spirit, the same way she had been a vessel for Wan Shi Tong's hatred. Because, essentially, that's what the Avatar was. A bridge. A vessel. A channel.

"I know what I have to do," she said.

"Did the Mother of Faces tell you?" Asami asked.

"She gave me some sound advice." Korra packed her things, one by one, hands shaking. She didn't want to tell Asami that she actually didn't know what she was doing, that she only had the barest of hints. But now that Koh had been vanquished, she had to focus on the task at hand. She had to stem the plague.

She bent over to cough, and her hand came away black.

"It's become worse. Much worse." Asami crossed her arms, as if indignant that Korra had not told her about it before. She seemed to forget that only hours earlier Korra had returned her face. "You can't hide it anymore, Korra. I'm worried about you." Asami didn't need to tell Korra that. She knew how bad it was, she knew how Asami cared for her. But her infection wouldn't last for much longer, not if she could help it.

"I will get better. Don't worry." Korra squeezed Asami's hand and led her away from the pond, still stained dark brown with the disease. "As soon as I clear up this blight, I will get better." I hope, Korra failed to add.

She did not want to leave Asami alone in this world. Not right after they had truly discovered their feelings for one another. But she had to acknowledge that as the Avatar, the world came first, and her personhood after. So she tucked her fear away in the nooks and crannies of her mind, and instead filled herself with resolve.

Shortly after the fight, when she and Asami had finally let one another go, Wan Shi Tong had demanded to know what the Mother of Faces told her. He wanted to know what she had learned about the plague, and how she had managed to get Asami's face back.

Korra herself did not completely know the answers to those questions, but when she stepped over the pile of fresh-smelling earth that were the remains of Koh's body, she knew that he was no longer holding those faces captive. If Asami's found its way back to its owner, perhaps all the faceless spirits, wandering lost and silent, would be able to move on. Perhaps faces thousands of years lost were finally returning to their owners. Korra liked the thought of that, but she knew as well as anyone that it was wishful thinking.

"We're going back to the Tree of Time," Korra said. She said it with such confidence and authority that even she had to admit she sounded like she knew for sure what she was doing. Of course, that was entirely untrue.

"The Tree?" Asami sounded upset. "But—"

"I know the last time we were there I had a… hard time."

"That's understating it," Asami muttered.

"But it's where my power is strongest. If I want to get rid of the blight, I'm going to have to do it from there." It was where the hatred was most intense—it was the wellspring from which the plague sprang, and Korra would have to block its source if she wanted to rid the land of it.

"So, what exactly are you planning to do?" Korra could read in Asami's voice something a little skeptical, as if she expected to be lied to. It wasn't an unsafe speculation.

"Remember what I did to Wan Shi Tong and Koh? The same thing, just on a bigger scale… it's a bit different, since I'll be doing it to the entire spirit world, but…" To be honest, she didn't know if it would work. But she did know that she had to do it. When she had touched those two faces inside that dark place... inside Koh's mind... she had known. She had known all along that her job as the Avatar was a conduit. For spiritual power, for love, for hate, for disease...

Asami grabbed her arm and stopped her in her tracks. "No."

Korra turned, concerned. "What?"

"No. You're not going to do that, not if you're going to get yourself infected, the same way you did with Wan Shi Tong."

"Asami," Korra smiled sadly. "I'm already infected. I doesn't matter, not at this point."

Asami's face fell. Korra did not like her expression, but she was thankful Asami could make one at all. It was a remarkable step in the direction of improvement. "Look, Asami," she continued. "I know you're worried, but this is something I have to do. I'm the Avatar, remember? There are certain things that come with the job. Some perks," she said, wrapping her fingers around Asami's hand and leading her down the path. "And some risks."

Asami sighed and let Korra lead her down the dirt path, toward the Tree. Korra could tell she wasn't satisfied, but she knew as well as any other that the Avatar's life was not her own. It belonged to the world, and if the world demanded it, she would have to deliver. It was just how things worked.

They walked the rest of the way in silence—a silence that was not exactly morose, not completely determined, but seemed to be colored with a strange mixture of complex emotions.

Asami did not let go of her hand until they reached the Tree. Instead of crawling inside, Korra sat down at its roots, in the wet rocks. A few tiny streams of water trickled around her, and she found the sound comforting. Water always made it easier for her to meditate. She sat down, coughed into her hands, wiped them on her pants and crossed her legs.

"Korra…" Asami started, but couldn't finish.

"I'll be fine, don't you worry," Korra said. She hoped she wasn't lying. "Whatever you see, don't interfere. Please."

"I can't guarantee that," Asami said.

Korra looked down at the water trickling by her. "Then… I'm sorry I have to do this." Korra looked up at Asami.

She slammed her hands down on the ground, the water rising around her and spreading like glass to cover her. She wove herself a cage of ice, thickened it, and breathed strength into it. It hardened around her, and when it had finished morphing into an impenetrable dome, Asami was at its edge, pounding away on its thick walls.

She did not know if Asami could hear her. She could barely hear her friend's fists hammering the ice, her voice muffled and desperate. "Asami," Korra started anyway, hoping that Asami could read her lips through the thick ice. "Remember that…" It felt weird to say it, almost. "I love you."

She closed her eyes, letting determination fill her up. She felt that familiar hatred, that pain, trickle into her, dripping like the creeks she had recently dried up to use as a fortress. It turned into a searing agony, an insurmountable anger, but Korra overcame. She kept the words of the Mother of Faces in her head as she meditated.

Mercy, mercy.

She breathed in that hatred, letting it soak into her bones, her lungs, her soul. She saw visions of saws cutting her open, saw herself burn in the purple conflagration of Kuvira's weaponry, she was confined and prodded and stretched and sliced. She absorbed the pain, letting it flow through her, until she could barely feel her limbs anymore.

The pain threatened to consume her, but when she felt her mind turn to dark thoughts or to the desire to destroy the agony, she summoned an image of Iroh. The sweet man whispered in her ear the wisdom he had imparted to her long ago, or what seemed like long ago.

Listen. Listen to yourself. Forgive.

She accepted the responsibility and the burden of the spirit world's torment. She took its blows, its hateful weight, until she felt like she would be crushed under its burdens. She could almost see the blight in her lungs spread through her body, darkening her veins and tightening her muscles. She shook with agony, unsure how much of this she could take.

And then there were arms around her, rending her visions in two. She was ripped out of her painful trance to find that Asami had smashed her way through her barrier and was now hugging her close.

"Asami," Korra croaked, voice taut with the burden of sickness.

"You can't do this," Asami cried.

You're endangering everything, Korra thought, her face screwing up in pain. "Asami, stop. Let me do this." Her vision was blurred with pain, but from the corner of her vision she could see the mark of the plague had manifested on her skin. It seemed to be crawling from the earth and into her, staining her brown arms a shining obsidian. The plague was still spreading through her body. She was not finished.

"You can't…" When Asami looked into Korra's face, and drank in her determination, she started again: "You can't do this alone."

The pain inside Korra tightened its grip on her legs. Come back to me, it said, in a harsh whisper that hurt Korra's ears. She was only halfway done—she had to get back to the source of that anger, before she died of it and left her deed unfinished.

"I'm the Avatar," she barked. "It's my job."

"Your job to carry the weight of both worlds on your shoulders? Alone? I don't think so, Korra; you're only human."

"Only? I'm human, but not entirely, Asami. It's too late. I need to do this."

"Then let me do it with you." Asami was crying now, releasing loud, desperate sobs. Korra looked up at her, at the earnestness in her face, and knew there was nothing she could do to get Asami to leave. A part of her was thankful for it. She'd rather not do this alone, especially if she wasn't going to get out of this alive.

Korra reached up and drew Asami close to her. Their foreheads touched, and for a brief moment, the pain subsided. Korra sighed, clenching Asami's arms, and again let that agony fill her up. Asami's hands gripped her elbows, squeezing tighter and tighter as the torture intensified, as she filled up with the same hatred that had infected the world. She gasped, holding Korra so tight she thought they would merge, right there, into one big pile of agonized, broken bones.

Korra knew that Asami now shared her visions. They both saw the horrible decay of the wide forests, the decimation of the spirit vines, the subsequent experiments and grisly exterminations. She saw people die before her, torn apart by the explosion of her own energy. She watched her latent power used to destroy buildings, towns, forests, people, animals, spirits. Their pain became hers, piling onto the already formidable intensity she bore in her bones. The agony increased with each death, the hatred multiplied, and when she couldn't take anymore, both she and Asami simultaneously opened their mouths to scream.

It was at that moment that the world went entirely dark.