This story is actually a chapter from another story I wrote with an OC. But since there is a lack of Itachi/Shisui stories, I thought this one could stand on it's own. No OC mentioned.

Action sequences are not my forte, but practice makes perfect. ;)

Disclaimer: Nooo, I don't own Naruto...

Even without his Sharingan activated Uchiha Shisui saw the flicker. It was his specialty, after all. Flickering was a basic Shinobi skill taught at the Academy, but Shisui had not only perfected it, he had transformed it into an art and made it into his own special technique. He was known throughout the Hidden Leaves as Shisui of the Body Flicker, a title he carried with a certain pride. So as smooth and quick as the flicker that appeared before him was, he was even quicker to spot it. And know who it belonged to.

"Itachi," Shisui greeted his cousin warmly. In return Itachi smiled at Shisui with the same warmth, but his eyes lacked what his smile reflected. Ever since Itachi had returned from that mission there had been something off with him. When ANBU and the Police had initially approached Shisui to keep an eye on Itachi he was reluctant, but Shisui had to admit that Itachi's recent strange behavior had warranted the request.

"Are you busy, Shisui?" Itachi asked. They stood on the training grounds, alone.

Shisui shook his head. "Sasuke kun wanted me to meet him here. He said he needed help with his kunai throwing." Shisui lied. The truth was that he was suppose to be meeting with Kakashi for a report; but, as usual, Kakashi was late.

"Sasuke…" Itachi became thoughtful, and for a second Shisui thought he saw a flicker of sadness in Itachi's eyes. It was fleeting though, quickly covered by Itachi's regular impassivity. "I am surprised he did not ask me to help."

Shisui simply shrugged. "I suppose he figured you would say no."

Itachi glanced behind him, and then turned back to Shisui, obviously distracted. "Come with me, my brother. There is something I need to show you."

Shisui raised an eyebrow. "Eh? What is it, Itachi kun? Something you can't show me here?"

Itachi shook his head. "No, it is something that I need to show you…. Elsewhere."

"Well? What is it?"

"It's… a new technique."

Shisui's eyes lightened up with the same excitement every Shinobi felt at the prospect of a new technique. "Ok… ok… let me just leave a note…"

He dug around in his pouch and found a piece of torn paper and a worn out pencil. Quickly he jotted down "Will meet you later" and pinned it to the training post with a kunai.

As aware as Shisui was of the flicker Itachi used, he was unaware of the Sharingan his cousin activated as he quickly jotted down the note.

Dusk had spread across the Hidden Leaves, and by the time the cousins reached the river the sun was slowly lowering itself, behind the mountains. The last rays of light that it beamed spread across the water, casting everything in a dim, blinding hue of gold. Itachi stood at the edge of the river, soaking in the warmth of the rays as it beamed on his face. He stared at the sun, burning his eyes.

"What is it, Itachi?" Shisui approached from behind. "Why are you standing toward the sun?"

Itachi sighed, and turned halfway. His eyes were lowered, staring at the leaves that were gently being blown across the ground. "You have been like a brother to me." He said quietly. "Closer to me than even Sasuke kun." He turned, so that he was facing Shisui. "You've helped me hone my Genjutsu to a new level. I am grateful to you, brother."

"Of course, Itachi. You know I feel the same way." A look of sadness crossed Shisui's face. "When Obito died it was hard for me. But you were my companion through it all. And though I lost one brother, I gained another in return." Shisui smiled. "And for that I am grateful to you." The smile quickly faded. Itachi stood before Shisui, his head lowered. All Shisui could see was the top of his head. "What troubles you, Itachi?"

Itachi took a moment before replying: "I don't want to keep you for too long. Kakashi san likes people to wait on him, but he won't like waiting on you."

Silence loomed over them. They both stood their grounds, silently weighing the implications of what was just said. "I don't know what you mean, Itachi."

Itachi raised his head slightly, looking up with his eyes. He caught the flicker of red from Shisui's eyes, and instinctly activated his own Sharingan.

"It's ironic, you working for Kakashi san against me," Itachi said. Slowly, he began to walk toward his cousin. "The same Shinobi who left your brother for dead, and now walks around with his Sharingan eye. Don't you find him disgraceful, violating the Uchiha Bloodline in such a way?"

Shisui glowered. "You've always been strange, but you've become stranger since joining ANBU. I suspected as much, but refused to believe what others had whispered." Shisui raised his hand and stopped Itachi from approaching any further, pointing his finger at his cousin's forehead. "Brother or not, I will not let you desecrate the name of our Clan, Itachi. I will see you dead before that happens."

Itachi slowly raised his head, and met his eyes with that of his cousins. Both eyes blazed bright red.

"You will not get the chance." Quickly Itachi raised his arm and thrust Shisui's hand away from his head, but within the instant Shisui was gone. Itachi blinked, and suddenly felt a kick to his back, sending him flying across the ground.

He quickly jumped to his feet, and jerked his head to the side just as the shuriken hit the tree behind him. For a brief second Itachi caught Shisui flickering before him, and seizing the opportunity he raised his fist and landed a punch into Shisui's chest, sending him into the water.

Itachi ran and jumped up, and was upon his cousin, his fist curled. He thrust at Shisui who caught it, and swinging around threw Itachi across the water. Itachi closed his eyes and was already performing the hand signs as he landed with a splash.

Standing on top of the water Shisui ran up to Itachi, grabbed him by his neck, and picked him up. "Itachi!" Shisui shouted. "You've gone mad! I don't know what you hope to accomplish but you are a fool if you decide to turn your back on the Clan!" Shisui froze. Time stood still. His emotions were running high, and he hadn't initially noticed that the Itachi he held looked different in his activated eyes. Kage Bunshin!

Itachi's voice came from behind him. "I will send you to Obito."

Before Shisui had time to react Itachi had struck him on the back of his head. As Shisui fell forward Itachi grabbed him by the back of his neck and rammed his head into the water with all the force he could muster. Itachi's clone, having broken free, spun around, and grabbed Shisui's arms, pinning them behind his back.

Shisui kicked violently, with incredible strength. Itachi felt himself being flung around, and one accurate kick quickly disposed of his clone. Even as the clone disappeared Itachi grabbed Shisui's arms with one hand, keeping the other one on his neck. He maintained his position, having to exert all his strength, and it seemed like hours passed before Shisui stopped thrashing.

Even after several more minutes of Shisui's stillness Itachi kept his grip firm, sweat pouring down his face and his back as the sun beamed its fading light. Had his senses not been heightened from the rushing adrenaline... had he not been looking and waiting... he would not have been aware of it happening. It was so soft, and so subtle, like butterfly wings grazing against his cheek, he almost missed it.

But it was when Itachi felt that slight sensation, that he knew for sure Shisui was dead. Slowly, reluctantly, he released his grip on his cousin. He stumbled back towards the river's edge, and at the last moment decided to give up and fell into the water. He sat on the rocks, the water beating and brushing against him. Breathing heavily he turned around and watched as the current carried Shisui away. His Sharingan eyes followed the body until it was out of view.

Goodbye, my brother...

He closed his eyes, his breathing still labored. I must test my new technique… to see if it was worth it… he closed his mouth and forced his breathing to slow down, taking air in and out deeply through his nose.

Breathe…

Breathe…

……

"MANGEKYO SHARINGAN!"