"Avatar," said the Mother of Faces. "It has been a long time."

Korra, still a little shaken up at the sheer might of this ancient spirit, felt relief creep back into her. If the Mother of Faces was familiar with her, she might be more willing to help her… unless, like with Koh, there was bad blood between them. Korra prayed fervently that Kuruk or any other thoughtless Avatar hadn't offended the giant spirit in the past. She could feel the power radiating from her like light from the sun, and had no desire to challenge it.

"Have we met, great spirit?" she asked as politely as possible, trying to hide her urgency.

"Yes, once before, in your most recent past life." Korra sighed. If it was Aang, she could be relatively sure that he hadn't done something awful to her. Her relief was solidified when the Mother of Faces continued: "It's a pleasure to see you once again."

Korra bowed deeply. "Forgive me for not recognizing you," she said.

"Ah, yes. Forgetfulness is the price you pay for reincarnation. But there is no offense to forgive." The Mother of Faces leaned forward, examining Korra with a face that appeared to have no eyes. It was a beautiful face, but somehow terrifying. If the reassuring breath of the giant wolf had not warmed Korra's side, she might've turned and ran. "What is it you want, young Avatar? Surely you do not wish for a new face. I have crafted yours quite splendidly." The spirit loomed over Korra, reading her. "No, it is not that. You have come about the disease ravaging the spirit world."

The Mother of Faces settled back down into her pond, green bark glowing with the light of the magic water. "I am sorry that I am unable to follow you back into the spirit world to help—my passage has been blocked by the blight."

"So I take it that you can't restore any faces in the spirit world, then," Korra said, visibly disappointed.

"No. Has Koh again stolen the face of the one you love?"

The one I love? Korra thought. "Yes. He has."

The Mother of Faces twisted in her pond as if she were in pain. "I do not know what he has against the Avatar personally, but I do know what he has against the world."

Korra decided she'd better glean what she could from the wise entity. "Please, tell me whatever you know."

The spirit settled down, bark creaking. "Since I am a sylvan spirit, I know much about the woods, in this world and the spirit one. I can feel the echoes of the plague from here, and I know why my son is running rampant across the dying land."

Korra leaned in a little closer, intrigued. The Mother of Faces went on, but seemed to talk past Korra and into the forest itself. Maybe, in her own motherly way, she was calling out to Koh when she spoke, as if he were in the shadows, listening to what she had to say. "It is anger and resentment that drives this plague, Avatar. Just the same things that drove my son away from me. He is enjoying the blight so very much because he has been afflicted with it for thousands of years. He is not unique among spirits—plenty of them are occasionally, and sometimes permanently, infected with the disease of hatred, but never before has this plague been so widespread. I'm afraid the spirit world is becoming more and more like him every minute."

"Like him?" Korra asked.

"He has been hurt, Avatar, quite often, and quite badly. I'm afraid that perhaps my parenthood is to blame. You see, he is the only spirit that was a direct creation of another. He is the only child in the spirit world—he had a beginning, and therefore, he has an end. In a way, he is almost mortal. He is filled with turmoil, trying to assess what this means for him. It is a matter of his identity, and he cannot come to terms with it. He had always been somewhat of an outcast when it came to the spirits. But he has had so many years to slowly bolster his resentment, he's no longer aware he has it. He will tell you he has nothing against anyone, he will tell you he does not feel, that he does not care, that his expressionlessness and indifference are innate. But they aren't—he, like you mortals, was once a child, and one day, many millennia from now, he will die. He has changed, and I would argue that it is his mortality that allows such change, that allowed him to turn sour and tricky and vengeful. Now that he is witnessing spirits whither away from the same affliction he has, he has never been more at home.

"I believe he is afraid to look at himself. He is afraid to accept his own situation in life. He is bitter and angry with me, with the world. That is why he steals my creations. And that is also why I create more for him."

"How…" Korra paused. She was about to ask something that she knew she shouldn't ask a mother. "How to I stop him?"

The Mother of Faces released an icy breath that may have been a sigh. "I do not know, child. His troubled disposition is so ingrained in him I am unsure how one would go about banishing it. I'm sorry I cannot help you, Avatar, but I can ask one thing—show him the mercy that no one else has."

Korra thought of Wan Shi Tong, and the way she had absorbed the hatred that consumed him. She never wanted to do that again, but she accepted that she might have to. And still, the plague she had accumulated grew inside her. The Mother of Faces, old and wise as she was, followed Korra's train of thoughts.

"You are touched by the blight," she said, not unkindly.

"Yes. Wan Shi Tong told me you might be able to help me heal."

"Wan Shi Tong… I felt his presence snuffed out some time ago. I believed he was gone forever."

"No," Korra said. "Just a little bit of a smaller presence, that's all."

The Mother of Faces smiled. "You cured him, then?"

Korra nodded. "I think so. But the problem is the blight never left… It just… changed hands." As if in response to her thoughts, the pain in Korra's chest intensified, and she clutched at it, holding in her coughs.

"It is an unfortunate outcome. However, you are bearing the burden well. You are stronger than that petty little owl ever was. And you are stronger by far than my son. I can tell by looking at you that you have suffered greatly and overcome all of it. You will endure what others cannot, Avatar. Remember that while the suffering of others drives them to revenge and hate, yours will only drive you toward wisdom. It is your advantage, being Raava's incarnation, and it is something that no one else has. Do not squander that advantage by giving into bitterness. It is bitterness that has torn my son from me…"

Suddenly the Mother of Faces looked up, past Korra and into some world beyond, one that she couldn't see or sense.

"And it is bitterness that brings him back."

Korra turned, following the Mother of Faces' gaze, but she only saw the forest behind her. She was about to ask what the great spirit meant when she heard the sound of a surprised scream. It seemed to come from far away, but resounded in her chest as if it had come from her own lungs. She panicked, momentarily, and another scream pierced the air. It was cut short abruptly, and Korra broke out into a cold sweat when she realized the voice had been Asami's.

"Go," the Mother of Faces said, urgently. "He's here."

Korra, without bowing or thanking the spirit for her help, turned and sprinted through the forest. She barely noticed the panting of the spirit wolf behind her, urging her forward. She had to get back to where she had left her body, to where she had entered this world, so she could get back to Asami, back to the source of the bone-chilling scream.

In a mindless panic, Korra threw herself back into her body, disappearing from the trees and plants and undergrowth of the giant, healthy forest. When she smelled that familiar stench of blight, and felt the soreness of sickness in her muscles, she opened her eyes.

Miraculously, she suppressed any expression when she drank in the scene around her. Wan Shi Tong was nowhere to be found. At the corner of the muddy clearing, beaming mercilessly, slithered Koh, wearing his usual face. Before her, Asami knelt, hands covering her eyes. When Asami heard Korra get up, she looked up at her, but she no longer had anything to look with. In place of her features was a stretch of empty skin, framed by her wavy black hair.

With an angry fire bursting in her heart, Korra forced herself to turn and look at Koh.

As if pleased with himself and more than willing to share his triumph, Koh morphed his face. With a flicker of shadow, he was wearing Asami's features. They were warped, frightened, twisted with the last emotion she had shown. As Korra looked into Asami's face, a face that was no longer hers, she clenched her fist and called upon the strength of the ancient spirits inside her.

The sickness inside her came to life with her rage. It spread through her, as if urged on by her hatred. When Korra entered the Avatar state, the pure light of her features was smeared grey with the hue of blight. The disease inside her urged her to lift her fists and summon all her strength. It told her to destroy the thing that had hurt Asami, to erase him from the world, to make him pay.

She listened.