A/N: Wow, I took a little longer with this one, huh? Thanks for the reviews :) I hope this chapter clears up a few of your questions.

Disclaimer: I do not own the TMNT.

Naito walked down another tunnel, ignoring the pain of his broken arm as he held it close to his body. His feet splashed in the water as he walked. He was tired and sore and hungry, but he couldn't bring himself to do anything about it. He only continued walking, heading in the direction that the family lived. He gave a sigh and leaned against the wall of the tunnel. The stone was cold underneath his skin.

He wanted somewhere to belong. He had wanted it for years. Years spent suffering alone. Now it was suddenly there. A family. A home. Love. All at the cost of his twin's life. Naito glanced back in the direction he had come from. His brother was back there. Probably already being eaten by the denizens of the sewers. Naito swallowed. His fault. Leo was dead. It was all Naito's fault. The turtle sank to his knees and tears streamed from his eyes. He hadn't wanted to kill Leo. He just wanted to talk to him. He wanted to be accepted. He wanted to be loved. Not feared. Leo was right about Naito. He was a monster.

Naito didn't know how long he had remained like that, but he knew he needed to move when he noticed a few roaches tickling his legs with their antennae. He rose to his feet and shooed the bugs away. A day ago, he would have eaten them for sating his starvation. He began his stumbling walk. Lack of food was making him weak. He continued, ignoring the ache in his gnawing stomach.

He finally stumbled into a dimly lit section of the sewers. Candles sat flickering on the stone floor. Naito didn't even acknowledge their existence as he shuffled past them. He passed three turtles lying asleep on the ground. He finally dropped to his knees behind the kneeling form of an aged rat. Naito stared vacantly at the ground. The old ninjutsu master turned at the sound and froze. His soft gaze was fixated on Naito, who sat bloody and battered before him, his right arm hanging limply at his side while his left arm was covered in bruises and minor cuts. The blue mask he wore was blood stained and one of his wooden swords was crusted with dry blood.

Master Splinter swiftly tugged Naito into a warm embrace, taking care not to jostle the young turtle's broken arm. Naito stiffened in the embrace. He hadn't expected it. Still, he had never felt so warm and comfortable before. So safe and loved. The old rat stroked Naito's shell with a gentle hand. He spoke softly, then. A whisper. "Leonardo...my son."

Naito's heart fell ad he suddenly felt cold. He began shaking and tears streamed from his eyes. The master only held him tighter and said that name again. Naito shook his head but could not speak lest he cry out his misery. He didn't belong anywhere. This was Leo's family, not his.

"I can't be who you are." He thought painfully to his brother. Leo was gone. He was gone forever.
Naito didn't remember when he blanked out of reality, but he was suddenly standing in front of the other three turtles. His body had been cleaned of blood and muck. His mask had been cleaned as well as his wooden swords. His right arm was splinted and wrapped. The three turtles stared at him for a moment. Naito didn't know what to make of it. What was he supposed to say? Suddenly the turtles all ran forward and embraced him. Crying his brother's name. Leo. Leo. Leo.

It was always Leo. Naito could feel a pang of pain each time they had said that name. Naito was silent. He didn't hug them. He didn't speak to them. He couldn't look at them. It was too painful. They thought he was Leo. He wasn't. He was Naito. He was the cursed one. He was the monster.

Time passed swiftly after that. His arm had healed. He was training with them. Alongside them. They called him Leo. He was learning to ignore the pain that came with the name. He was learning to respond with words again. To talk. He excelled at training. His drive for ninjutsu was unequaled by his brothers. His brothers? When had he called anyone other than Leo as his brother? Naito ignored it. They were his brother's. They looked similar enough and they loved each other enough to be brothers. Though Leo had never loved Naito. It was the exact opposite. Leo had hated Naito while Naito had loved Leo.

Naito was hesitant when it came to balance training. They were told to walk across a beam that stood more than a few feet off the ground. It was unsettling. All the memories of falling and the painfully of a cable around his arms came and attacked him. He knew then that he was afraid of falling again. So he strove for balance and excelled more than his other brothers at it. Just as he did with every lesson.

Raphael began taking to tease him and start fights with him. Naito was afraid of losing control and attacking his brother like he had to Leo. He avoided Raphael as much as he could and only defended himself when Raph got physical. Donatello had stopped trying to strike up conversations about his scientific thoughts with Naito. Apparently Leo had been the only one that Don talked to about science. Michelangelo spent less and less time playing games with Naito. He turned to teasing Raphael instead.

Naito felt alone. Alone again. Except he had accepted it. He accepted this life as the punishment. The punishment for killing his twin brother. He promised to protect the other three as his price for redemption. He would be Leo for them.

-.-.-.-.-.-

The aged sensei watched Leonardo perform the kata once more. He couldn't believe it. Leonardo had learned it so swiftly. The little turtle finished with a bow and regarded his master with those sad gray eyes of his. Master Splinter nodded and stroked the tuft of fur under his chin.

"You may go play with your brothers, Leonardo."

The child winced at the mention of his name and glanced at his brothers. They were waving around toy airplanes and cars. He turned back to Master Splinter and swallowed.

"Sensei, I'd rather train. Could you teach me something else?" He asked in his always polite tone. When had Leonardo become polite? He had been just as brash as Raphael only a month ago. Master Splinter smiled and nodded. "Of course, Leonardo, but only once more—I am not as young as you, my son." He answered. The little turtle nodded. "Hai, Sensei."

Master Splinter decided to try something else. "This is a test, Leonardo. I want you to sneak up on your brothers, my son. Try to take one of the toys without their noticing."The ninjutsu master spoke calmly. The blue masked turtle glanced at his brothers and eyed the deep shadows around them. He turned back to his master and bowed before walking past Splinter and entering the shadows of the lair. Master Splinter noticed then, how dark it really was in their home. He turned back to his three sons who were content with their toys.

One of the shadows wavered and Donatello turned to look at it. He called Raphael and Michelangelo over and they stared into the shadows. Master Splinter nodded until he noticed a small hand snatch a toy car from behind the three turtles. He stared. Leonardo had never been nearly that capable at moving in the shadows. How was he able to do that? That would have taken years of practice.

"Master, I have the toy. Did I pass the test?"

The aged master turned to see his son, half in and half out of the shadows. It was as if he belonged there. Splinter stared for a moment before smiling and patting his son on the head gently. "Yes, Leonardo. You did well. Go ahead and practice your katas, I will be back in a little while, my son."

The blue masked turtle fidgeted before nodding.

Master Splinter turned and made his way out of the lair. "I am leaving; I will return shortly, my sons. Stay here." He said before exiting and making his way into the sewers. He walked. His mind wandered as he walked. His son was different. Leonardo had changed much since he had gone missing. At first, Splinter thought that it was just trauma. Leonardo had been hurt badly and he surmised that the child was very afraid of something. After some time, though, it was apparent that he was not afraid. The only thing he feared was heights. Leonardo had changed. He was no longer afraid of the dark. He was not interested in science or technology. He would not quarrel with Raphael nor play with Michelangelo. He actually had an interest in ninjutsu. Leonardo had definitely changed—no. It was as if his son was someone entirely different.

Master Splinter halted. He needed to speak with Leonardo privately. He needed to know what had happened—even if his son began crying again and became almost catatonic—he needed to know what had happened!

He turned on his heel and rushed back to the lair. He entered silently and froze at the sight before him.

Raphael held Leonardo pinned to the ground and shouted at him while Michelangelo and Donatello watched. Leonardo's eyes were screwed shut and he was shaking—but not from fear. It was something different. Master Splinter rushed in and scooped Raphael up quickly. "That is enough, Raphael. Never treat your brother in such a manner!" Splinter barked at his son before sternly setting him down in a corner. "You will remain there for the rest of the night, Raphael. Think over your actions. I expect an apology for your brother."

Master Splinter turned to Leonardo, who sat with his arms wrapped around himself, shaking uncontrollably. The ninjutsu master lifted his son into his arms and disappeared into a separate room, closing a makeshift wooden door behind him. Master Splinter sat down on a tatami mat and held his son close to him. He whispered soothing words and gently stroked his son's shell.

"Leonardo," Master Splinter began.

"I'm not Leo." The child whispered. He had stopped shaking and tried to pull himself away from Splinter.

"Leonardo, what are you," The sensei began again.

"I'm not your son! I killed Leo! I'm… I'm his twin brother." He said. Master Splinter stilled and the young turtle managed to remove himself from Splinter's grasp. He then knelt before the aged master.

"My name… is Naito. Leo is—was—my twin brother."

Master Splinter stared and he knew that the young turtle was right. He wasn't Leonardo. There was no way he could be. The rat dropped his gaze to his hands. His eldest son. His child… was dead. His Leonardo was most likely lying dead in the sewers somewhere. He was probably just bones and a shell by now.

"I killed him with his own weapons. He came searching for me and I attacked him."

Master Splinter stared at him, unable to comprehend it, but he knew it was true.

"I know you want to kill me now." Naito said; his gray gaze penetrated through Master Splinter's heart. It was so much like Leonardo, but, this child had taken his son from him. He had taken Leonardo from him. Master Splinter moved forward, his strong hands wrapped around Naito's throat and tightened. Naito had taken his son from him! He didn't deserve to wear the mask and weapons of his son! He didn't deserve to breathe while his son was decomposing out there in the sewers.

"I deserve it. Don't hold back." Naito gasped, finding it harder to breathe, but holding himself still as the grief-stricken father choked the life from him. Splinter flinched back at those words, quickly releasing his hold on Naito. He backpedaled, sickened with his own act. He had tried to kill a child.

Naito stared at him with those sad gray eyes and Master Splinter looked away. This was the one who had killed his son. Yet, how could he hurt this poor child? Naito had been alone for eight years, if he was telling the truth. He had been forced to fend for himself and depend on no one else. It would have been a harsh life. None of his sons would have survived whatever horrors that Naito had. Splinter turned to stare at the young turtle.

"Tell me the truth. What happened all those years ago? How did you become separated from Leonardo?"

Naito closed his eyes and swallowed before nodding.

"Before I mutated, when I was a normal turtle, Leo and I hatched from the same egg. After awhile we were packed into a glass jar with the other three and we were dropped into the sewers by accident. We fell into the ooze and there was nothing but pain for me. Leo was fine, the others were fine, but I reacted badly. Something was wrong. I was blinded. There was nothing but darkness. I was scared, so I panicked. I waved my arms and legs and I was suddenly falling. I was swept away by a powerful current of water. It pulled me far away and it dragged me under until I couldn't breathe. The pain began to fade, and everything went dark."

"After that, I woke up changed. Half of my body was like this… the other half was still the same, just bigger. I was… in pain. Always in pain. I lived off of what I could find… until Leo found me. He realized who I was and he began to care for me—not very well though. He gave me rotten scraps and I was forced to drink dirty sewer water. One day he left and he never came back."

Master Splinter stared at Naito. This child was telling the truth, he knew it. The old rat could not bring himself to look at the child, but neither could he ignore the pity that surged deep inside of him for Naito. The child who killed his eldest son. Master Splinter finally turned his gaze up to the young turtle and found himself lost in those silver gray eyes. Those deep sad eyes. Splinter was torn between pity and hate. He could not toss this child out and have him be abandoned once more. Splinter cursed under his breath. He should have made sure that he had not left any of the baby turtles behind when he found them eight years ago. He should have searched harder. He would still have his son if he had.

Yet fate had decided that this was to happen this way. Splinter had had a hard enough time caring for four healthy baby turtles. How could he have possibly cared for a terribly deformed fifth child? He would have been forced to kill it. No doubt. Master Splinter turned his attention back to the child and swallowed. He knew what he had to do.

"You killed my eldest son. You took him from me. Fate did not allow you the life he had, and now it offers it to you, although it is for a price. You will take Leonardo's place in this family. You will be my eldest son from now on. Never mention the name Naito or your history to anyone else. Cast your name and past away, it is no longer yours."

Naito-Leonardo stared at him, unable to believe the ninjutsu master.

"Master, I... You can't trust me. I am not safe. There is something inside of me... it makes me want to hurt people. I'm a monster and-"

"Quiet. Based on what you have told me, I would not believe it if you were not scarred by the life you lived. Your past is one of blood and violence. I see that something dark lurks within you. I saw it when Raphael attacked you. You managed to keep it at bay, which is a good thing. I will teach you to control it... Leonardo."

The little turtle stared at him and nodded. The aged master sighed and dropped his gaze to the ground. They were both silent for a few minutes until Splinter stiffened and shot a glare at Naito-Leonardo. "Leave, now. Go outside and meditate." He snapped angrily. The youngster quickly darted out of the room.

"Go... go before I change my mind..."

-.-.-.-.-.-

Naito-Leonardo, fourteen now, bit his lip as the cane whipped out and struck the back of his legs. He screwed his eyes shut and released a deep breath. He stood still though. If he move, it would only get worse. His adoptive father had taken him in, despite the cause for the real Leonardo's death. He was trained harder than his adoptive brothers and bore far more responsibility than them. It was one of his prices to pay.

The cane whipped against the back of his legs again and Leo gritted his teeth. This was another price to pay. He had failed his master and was now receiving punishment for it. He had made another mistake. Leo had gone deeper into the sewers and had found a rabid dog. He hadn't meant to kill it, but it had attacked him. It had wanted to tear his throat out... and it was sick. It was sick like him. Leo had actually felt something stir deep inside of him when he cut through the dog's neck with the katana. It was a revolting feeling. The feeling itself was not one of revulsion. No, it made him revolted. He had felt a sense of pleasure when he killed the dog.

He told Master Splinter as soon as he had returned and the sensei was none too happy.

"Kneel."

Leonardo obeyed without hesitation.

"I apologize, Leonardo."

Leo flinched at that, his eyes snapped open and he turned his gaze up to his master. "Master, I don't understand."

"I forced you to suppress something, Leonardo. Something that cannot be suppressed. You have a monster deep inside of you, one that must be fed."

Leo stared at his sensei in horror. They had both spent the past six years using meditation and willpower to destroy the monster inside of him. They had maimed it. They kept it chained up. They kept it imprisoned with meditation and calmness. Control. He had developed his control over the years to combat this very monster. How could his sensei say that they had been wrong?

Leo stood abruptly. "No. No, you're wrong. It can be controlled. It was just a slip up, Master, nothing more. I can still control it."

His master eyed him carefully. Sadly even. "One day, Leonardo, you will realize that I am right. One day, you will unchain the monster. One day you will kill a human and you will find that you crave it. I am sorry, Leonardo. There is nothing I can do to save you."

Leo trembled and fell to his hands and knees. Six long years of pain and torment. It was all for nothing. He was a monster. Not even Master Splinter had any hope for him.

"When you do kill, Leonardo, make certain that it is not an innocent. Be certain that if you take a life, it is the life of a killer. There are few in this world that deserve death, my son. Those who do… are yours."

-.-.-.-.-.-

The aged master watched his son carefully. He had waited for this day for the past twelve years that Leonardo had been under his tutelage. He had known it would come. Every year, he waited. He waited with bated breath, hoping it would not come but knowing that it would. Despite the death of the original Leonardo, Master Splinter had learned to love this Leonardo. This was his son. He would do anything for the blue masked turtle before him. He steadied himself and his calm gaze bored into his son's gray gaze. There was no anger in Leonardo's eyes. No fear. No happiness. Only a mix of relief and guilt.

"When did this happen?"

"Three weeks ago, Sensei."

"Three weeks ago. How many have you killed?"

"Nineteen, Sensei."

Splinter nodded at that. "You followed the rule?"

"Yes, Master."

Splinter sighed in relief.

"But," Leo began. Master Splinter stiffened.

"Raphael saw me. He saw me kill the arsonist-murderer."

Splinter's eyes flashed angrily and his hand whipped out, striking Leo across the cheek. The turtle took the blow, he had taken quite a few over the past few hours. He rubbed the spot where his father had backhanded him.

"You were to be careful, Leonardo. You were not to be caught, least of all by any of your brothers. Has Raphael said anything to Michelangelo or Donatello?"

"No, I struck a deal with him, but… It causes another problem, Master. He wants to know about… about those three days that…" Leo said, fumbling over the words and trying not to hurt his father with memories of the past.

Master Splinter stiffened. His eldest son had not needed to finish the sentence. The aged master inhaled and exhaled slowly. "Do not tell him anything about who you once were. Make up a story if you must, but your brothers can never know about your true nature or your past."

"Hai, Sensei."

-.-.-.-.-.-

Leonardo made his way through the sewers at a casual but brisk pace. He was on his way to Leatherhead. He needed to fix the root of the problem.

Leatherhead had seen one of Leo's brief visions of the past and that raised suspicions. Questions. Leatherhead knew nothing of the accident, but he was now suspicious. He had seen blood. Blood raised plenty of questions on its own. Leonardo was determined to make things right. He would clear all suspicions with his story. He had come up with a story about him becoming lost in the sewers and finding a dead body before nearly falling to his death in that chute. It was believable. Better yet, it explained the vision that Leatherhead had seen as well as Leonardo's past fear of falling. He couldn't find any flaws in his story, and he doubted that Leatherhead would dare question it even if there were any.

He turned a corner and froze. Something wasn't right. His eyes darted about and he could feel his muscles tense. What was going on? Was he being followed? Leo's gaze darted the dark tunnels. He couldn't see anything. Leo's features settled into a fierce feral look. Whoever was following him or whatever was happening was most likely not friendly. Leo allowed his body to relax and he fluidly slipped into the shadows along the walls of the sewer tunnel. He closed his eyes and listened. The dripping of water from a rusty pipe became his metronome.

Drip.

Drip.

Drip.

The sound of the water softly streaming to its destination was near silent. Leo listened carefully. He could hear nothing else other than the sounds of the sewers. He started to move out of the shadows. Suddenly, he froze again. His eyes snapped open. There it was. A lull in the water current. He could hear the water moving out of its normal path. Someone was here. Someone had been following him. Leo's gray gaze turned to a dark form standing just several feet away. Leo grimaced. It was Raphael. Who else would be following him right now and carried a shell on his back?

Leo remained in the shadows. If Raph was following, no doubt he wanted to confront Leo. Raphael glanced around and grumbled under his breath before passing by Leo. The older turtle waited for his brother's footsteps to recede into nothing before he slipped from his placed and moved through the shadows to a detour to Leatherhead's lair.

-.-.-.-.-.-

Aboveground, the night had set in on the city that never sleeps. The sounds of the city were only interrupted by the constant wail of police sirens. The sky was dark and yet, it was lit up by the light from the city. The city's light cast a sickly glow over the clouds above. The shadowy figure standing on a rooftop yawned. He was not interested in the sky right now. He turned and sprinted across the rooftops.

He dropped into an alley and traced a symbol into the ground with dried wood and lighter fluid. He then clicked a lighter to life and the fire crackled as it spread over the symbol. He quickly scaled a building and continued his sprint. He arrived at a warehouse and repeated the ritual, soon another similar symbol burned bright on the warehouse. The flames flickered and burned against the dark sky.

He sprinted away, traveling to several similar locations and burning the symbol in each one but two. He arrived at an apartment building and painted the symbol in crimson paint, the color of arterial blood. He visited one other location and stood outside of the abandoned warehouse. He stood there for a moment. Silent. The wind breathed by and he found a smile on his features. He turned from the warehouse and walked away. The night soon swallowed his retreating form.

-.-.-.-.-.-

"I had no idea…" Raph managed as he sat at the kitchen table across from Leo. His older brother had just told him about how he had stumbled across a dead body when he was eight and fell down a shaft and nearly to his death. Leo nodded, keeping his features solemn. "I never wanted to tell any of you what happened. It was hard enough for me to live through it. I didn't want you guys to worry about it… I knew it would only scare you three at the age we were. I only told Master Splinter. That's why he spent so much time having me meditate when we were kids. It's also why I was so afraid of heights, Raph."

His red masked brother nodded numbly, staring at the steaming mug of hot chocolate sitting in front of him. Leo sipped from his own mug. He glanced over to the blue couch, where Mikey and Don were watching the Avengers. He chuckled as Mikey cheered and Don glanced at the young turtle with an annoyed expression. "This makes up for everything, Raph. I'm glad I never told any of you what happened. Seeing Mikey and Don like that makes up for all the pain I endured. Seeing you messing around in the garage makes up for it. Seeing the way you three interact… it makes everything worth it. All I ever wanted was to keep you three safe and happy."

Raph turned his gaze up to Leo and he smirked. "It sounds a little sappy, Leo. Like a Christmas special."

Leo rolled his eyes and sipped some of his hot chocolate.

"Don't get me wrong, bro', I'm grateful that ya' spared our childhood the horror of somethin' like that. Just don't hide anything else like that again, alright? We're yer' brothers. Ain't nothin' ever gonna change that, Leo."

Leo glanced down at his hot chocolate. That should have made him feel better. It was supposed to be a reassuring statement. So why did a pang of guilt fill him? Why did Raph have to say that? He wanted to tell Raph the truth then. He wanted to tell his brother, but instead he kept his mouth shut. Leo smiled at his brother and nodded. "Of course, Raph."

The red masked turtle nodded and shuddered. He rubbed his arms and looked uncomfortable. "Geez, too much touchy-feely crap. Let's go watch some T.V. or somethin'. I'm tired of this sap-fest."

Leo's smile fell from his features as soon as Raph turned his shell to him. Raph made his way to the couch, Leo made to follow him until a hand gently rested on his shoulder. Leo turned to face his sensei. The elderly sensei's eyes questioned but his mouth never moved. Leo glanced back at Raphael and to his sensei. He nodded and made his way to the couch.

Master Splinter walked towards the armchair and sank into it with a heavy sigh. Mikey munched on popcorn noisily next to Don on the couch. Raph grinned at Leo as the older turtle stood next to him behind the couch. The two vaulted over it, hot chocolate mugs in hand, and landed on either side of Don and Mikey.

They sat there no longer than a minute when the movie was interrupted by an odd sound and a news reporter suddenly took over the television screen. It was the same woman as on the last report. The turtles exchanged surprised glances and turned back to the television. Master Splinter frowned.

"We interrupt your usual programming for an important news report. There has been new evidence about the recent gang activities that causes police to believe it was not gang activity. This symbol," the reporter said, gesturing to a photograph that appeared next to her. The image was of a flaming triangle with a smaller circle attached to its base. "Has been found at every crime scene, including a homicide victim's apartment. Police have now confirmed that this is no longer gang violence but a series of murders committed by one person. This person is a dangerous serial killer and has been seen only sparingly. Eyewitnesses speak of a dark figure about five feet tall, but nothing else. They have taken to calling him 'Retribution' because of his victims and the symbol he uses—which stands for justice and punishment. All of his victims are criminals that have committed major felonies. Police are searching for Retribution as we speak. It is advised that everyone remains indoors at night. Thank you."

The television screen turned back to the Avengers but no one was watching now. The turtles were buzzing with questions and shouts while Master Splinter stared at his eldest son. Leo remained silent and stared at the television. His hands were shaking. He felt an unfamiliar sense of panic rise in his chest.

He hadn't made those symbols. Someone else did. Someone was playing with him.

A/N: Thanks for reading, I hope I answered the question about Leo-Naito... stuff... anyways, please review. The link for the symbol will be posted on my profile if anyone is curious enough for a look.