Earth. Fire. Air. Water. Only the Avatar can master all four elements and bring balance to the world.

Tarrlok wasn't the Avatar, but he was once a formidable water bender. He and his brother discovered their bending abilities as young boys growing up in the Northern Water Tribe. They spent many happy days playing in the snow, and sometimes at the edge of the lake, building snowmen and sending sprays of freezing water at each other. Their favorite activity was to carve two little sleds out of solid ice, one for each of them, and race down the slopes with the cold wind bracing their ruddy cheeks.

Their father, Yakone, watched the young brothers from a distance. Yakone was once the crime lord of Republic City, the metropolis that Avatar Aang had founded to bring the four nations together in harmony. Yakone had also been a notorious bloodbender until Aang took his bending away. He then fled Republic City under a new identity and started a family, but never stopped having vengeance on his mind and hatred in his heart. As he watched his young sons command the water, snow, and ice, Yakone knew his sons' destinies: they would become bloodbenders, kill the Avatar, and avenge their father.

The good days were behind them. Tarrlok hated every moment of his training, but it made him a dangerous fighter and the possessor of a dark, secret art. Bending did not bring him joy, but it was a part of him.

And now it was gone.

Right now, Tarrlok was behind bars in a cold and empty attic on a deserted island. He had been there for slightly over a day, but felt like it had been forever. Amon, the leader of the equalist movement to cleanse all benders of their impurities, had taken his bending away and then locked him in here. As if that were not enough, Tarrlok soon learned that Amon had been his estranged brother all along. He vaguely remembered a visit from the Avatar and her friends while he was in this cell. They asked him a few questions, listened to his story, and left.

Tarrlok was dazed and weak. His once impeccably groomed hair fell in disheveled locks around his face. He willed himself to pull droplets out of the air, but he could no longer feel his element. A river that used to flow inside him had evaporated. He would have cried but that water had dried up too. Occasionally, his despondency would be interrupted by fleeting memories of Amon, grown-up Noatak, Korra, young Noatak, and the equalist task force. Tarrlok wondered if he would lose his mind in this cell.

His dejection was punctured by the sound of footsteps and the attic door being unlatched. He heard a man's low voice and did not look up, assuming it to be Noatak. But he heard another man's voice, this time younger, and then another's, decidedly more chirpy. Then came a woman's voice he knew, gruff and hard, and another voice he recently became acquainted with, silky and refined, all talking together in low tones. But it was the final voice that made him look up.

Standing in front of him right now were Councilman Tenzin, Mako, Bolin, Police Chief Beifong, Asami, and Avatar Korra. They gathered in front of his cell. With a flick of her wrist through the air, Chief Beifong sliced the iron bars clean open.

"Are you alright, Tarrlok?" Beifong asked brusquely. "Can you stand?"

Tarrlok slowly got to his feet. "I don't suppose you're all here to rescue me."

"Ehhh," Bolin shrugged. Tarrlok never understood Bolin's role in anything.

Beifong stepped forward. "Amon's cover has been blown. The public has discovered that he's a bloodbender, and Team Avatar just informed us that he's your brother. Noatak is now on the run."

"So his revolution failed."

"For now," said Tarrlok's former colleague Tenzin. "There are still equalists causing trouble in the streets, but the movement has been severely discredited. We have to capture Noatak and bring him to justice. We need your help."

"I would gladly be of service, but I don't see how," said Tarrlok. "In case Team Avatar didn't inform you, he took my bending."

The group exchanged a quick look among themselves.

Tenzin furrowed his brow. "Tarrlok, what you did at City Hall was not only unconscionable, it was criminal. Bloodbending is a heinous practice that has been outlawed for a reason."

"Like I said," Tarrlok said wryly, "it won't happen again."

Beifong glared at him. "If you ever bloodbend again, the penalties will be severe. You will be put away for life."

Tarrlok gritted his teeth. "Is this some kind of joke? Are you mocking me?"

"He took away my bending too," Beifong replied quietly.

Korra walked towards Tarrlok. "And mine."

Tarrlok turned to the Avatar in surprise. It was the first time she had spoken to him since they arrived. Korra stood close to him and placed her hands on his shoulders. "We need you on this mission. He's your brother and you know him. Besides," she said as she moved one hand to his forehead while placing her thumb in the centre of his brow, "you're not so half-baked a water bender yourself."

Korra gazed into Tarrlok's eyes with an unfathomable expression. Tarrlok looked right back into hers. All of a sudden the air stood still, and everything fell silent. After a heartbeat that seemed like a lifetime, the air around their feet started to move round them in a circle, and soon the two were enveloped in a rush of swirling wind. As he stood face-to-face with her in the eye of the vortex and looked into her ocean blue eyes, he watched her change. Something luminous swelled within her until she burst with light, her eyes shining a brilliant white. She had entered the Avatar state. But before he could properly take in her transfiguration, a jolt of energy shot into him and obliterated his senses with a flash of cool, pure brightness. The force nearly knocked him to the ground. However, when he caught his breath, he was standing taller and stronger than he ever had in his entire life.

"Avatar Korra, what…what did you do?"

"Tarrlok, think fast!"

Tarrlok whipped around and barely registered Mako's voice when he saw an arc of water flying toward him. Mako had opened a skin of water and flung the contents at the former councilman. Tarrlok shot out his arm and caught the water in mid air. He held it steady for a moment, marveling at his regained powers. He froze the water into shards of ice. Then he melted the shards into liquid again and slowly pulled the orb of water towards himself. Tremendous energy flowed between his body and the water hovering between his hands; the river was coursing again.

However, before Tarrlok could fully take in his transformation, he was interrupted by a sharp pain in his chest. He looked down in confusion. Blood streamed down the front of his tunic. Korra quickly drew the water from his hands and placed it over his wound to heal it.

Beifong's snarl snapped him back to reality. "I've implanted a Radio Tracking Disc right above your heart. We'll be monitoring your location at all times. Don't even think about going rogue on this mission. This disc also functions an exploding device, and Korra has both the clearance and the ability to detonate it."

Korra's shook her head vehemently. "I don't want to detonate—"

"We've received intelligence that Noatak is headed alone towards Yu Dao, the former Fire Nation colony in the western Earth Kingdom," Chief Beifong cut off the obviously distressed Avatar. "He took an ostrich-horse, which should be easy to catch up with given the right equipment."

"Korra and Tarrlok, your mission is to find Noatak and neutralize him. The Avatar the only other person in the world who can take a person's bending away. But you two must work together because he is extremely dangerous. Tarrlok, you must be shaken from your recent defeat, but Noatak had the element of surprise—"

"I'm ready for a rematch with my brother."

"Good," the Chief nodded. "A special team will be following you from a safe distance. After you have neutralized Noatak, radio the team and he will be arrested and brought back to Republic City to face justice."

Chief Beifong then nodded toward Tenzin. The Master Air Bender cleared his throat.

"Tarrlok, the council is determined that you, too, shall face justice for kidnapping the Avatar and bloodbending so many people at City Hall. However, in return for your cooperation on this mission, the council is willing to consider drastically reducing your charges. We can negotiate the details upon your return."

Tarrlok lowered his head and sighed. "Fair enough."

Asami, who had been standing quietly next to Korra all this while, spoke. "I'll give the both of you a ride back to Republic City tonight. It's now 7 in the evening. Pack your bags and get some rest. At midnight, you'll leave for Yu Dao in Future Industries' All-Terrain Sato Mobile. You'll be able to catch up to that ostrich-horse in no time."

She then turned to Korra and held her friend's hand. "I'm sorry you can't bring Naga, but she can't take the both of you and it will be hard to find food for her in the desert. This Sato Mobile is special, it runs on water." Korra squeezed her hand back.

"Well alright then!" Bolin burst the heavy atmosphere with an excited clap and a large grin. "The Avatar and evil-former-councilman Tarrlok will go on a hunt for his even-eviller brother, while the rest of us will stay behind and clean up the equalist mess.

"Hey," Bolin turned to Tarrlok, "isn't it ironic how you once wanted Korra on your task force to capture Amon, but now you're on her task force to capture him and now it turns out that he's your brother Noatak?"

"Shut up, Bolin," Mako punched his younger brother in the arm and shuffled him out. The rest followed suit.

Tarrlok was the last to leave. As everyone else filed out of the attic, he put his hand over the part of his chest where the Radio Tracking Disc had been implanted. The entry wound was slightly raw but otherwise healed. If he stood very still, he could feel it buzzing gently.