He could recall it perfectly; the memory seared into his consciousness. Itachi had been four years old then, a toddler in the eyes of the world but a genius among the Uchiha. As a result, he had been brought to see a mountain of corpses; to see the reality of his existence as a shinobi.

"Father," Itachi whispered as he stared at the corpse of the Iwa-nin he had just killed. "I don't understand ... why did the shinobi try to kill me?"

"This is war," Fugaku replied calmly, a hand on Itachi's shoulder. "Strangers kill each other for genuinely senseless reasons. Never forget this sight, my son..."

"Never forget."

"This is war."

Itachi never forgot.

The funeral came after. It was a sombre affair.

"Lord Third will take full responsibility and retire."

Minato assumed the role of Hokage. Not Fugaku.

The Uchiha grew incensed.

Dissent began festering amongst their ranks, their loyalties questioned by a suspicious Leaf.

Then came a pivotal encounter. "The only way there is meaning in life is if it is eternal," whispered the snake sannin.

Itachi was confused.

"There isn't truly anyone who wants to die," he asked the cackling corvids following his failed suicide. "Is there?"

Pessimism.

Nihilism.

Existentialism.

Then...

Hope?

"You'll have a little brother or sister," Mikoto said to the young Uchiha, her lips curled in a small, happy smile.

"Huh?"

"The baby will be born in the summer," she said.

The baby was born in the summer.

"His name is Sasuke," Fugaku uttered with a bellowing laugh. Itachi was surprised; his father almost never smiled. "Sasuke Uchiha... Sasuke. We'll raise him never to dishonour his family name."

The baby was a crier. A relentless one. Eternally fearful... until he wasn't.

"It's okay now," Itachi cooed, cradling the infant as a demon fox rampaged across the Leaf. "I know. It was a little scary. Don't worry, I am here. Big brother will protect you."

"Hehe!" Sasuke giggled, carefree. Itachi was surprised; his brother only ever cried.

The demon was subdued. Lord Fourth was dead; the Third was reinstated with Fugaku overlooked.

The Uchiha grew incensed.

Dissent continued to fester amongst their ranks, their loyalties questioned by an increasingly suspicious Leaf.

Time passed.

Life was good. On the days the child toddled not on Itachi’s trail, he spent hours staring in a ponderous haze as the world went through its phases. Sasuke was a marvel. A genius. Everything Itachi was and more.

Much more.

Often fixated on the oddest of things. Ponderous. Patient.

"This is a core jutsu of our clan," Fugaku said as he demonstrated a fire-style technique, "Katon: Gōkakyū no Jutsu!"

Itachi copied him perfectly. Fugaku was impressed.

"That's my boy!" he said with a hearty laugh.

"Hehe!" Sasuke giggled from behind them. The toddler toddled forward before aping the duo. A beach ball-sized flame leaked from his lips before fizzing out.

"Hehe!" Sasuke giggled again, staring at the twisting haze of his technique with that enthralled expression he tended to wear. Itachi looked to his father; the older man was similarly gobsmacked. The toddler toddled off, distracted by a passing butterfly.

Time passed.

The toddler had grown; a kid now. Sasuke, the promise of a bright future. Itachi stared into the child's crimson, hateful eyes. Their parents lay by the child's feet. Unmoving.

Dead.

“...Why?” Sasuke asked. Itachi stared on impassively, aching as he envisioned the path he sought to set his child on.

“Why?” he asked again, trembling.

“...Curiosity,” Itachi replied, gaze unflinching as he desperately fought back tears. “I wished to measure my vessel; my worth.”

His child chuckled. Cackled. “Your worth?”

Sasuke's eyes bled red; Tears of blood ran down his pale, full cheeks. His essence blazed. Blossomed! The air wrapping from the build-up of chakra. Sparks became an inferno, enveloping his entire body.

Instinct honed by years of battle was all that saved Itachi's life.

The child flickered into his face, courtesy of Shisui—bless his heart. With a harsh crack, a wooden pillar across the room disintegrated. The child pulled free his arm from the ruined fixture as he turned to face Itachi.

“Baby brother,” Itachi said, lying, “you’re weak. Pathetic. Do you wish to kill me? Settle for hating me instead … Hate me and live like the failure you are. Continue clinging unto your worthless existence for as long as you can; this little I grant you for the sake of my amusement.”

The child was upon him the next moment, fist blurring towards his forehead. Itachi flickered out of harm's way, training his gaze on the child as he called upon his dojutsu.

"Tsukuyomi."

The child collapsed like a puppet with its strings cut.

Time passed.

The kid had grown; a teen now. Sasuke, his beloved child. Eyes red like two pools of blood rebuffed his genjutsu. The child flickered before him. Itachi raised his kunai, instinct honed by years of battle, once again saving his life.

“Hello, Itachi,” his child said, dismissing Kisame's counterattack with admirable skill.

“Sorry about dragging you into this,” Sasuke told his partner. “Kisame, right? I hope you don’t mind if I and my brother catch up a little.”

“Yes... Itachi, you never told me you had a little brother. I thought you killed off your entire―”

“Kisame! Close your―” Itachi ordered. Sasuke smiled fondly.

It was already too late; it seemed.

“Sōzōamatsukami: Yomi’s Garden!”

Kisame fell to the ground, limp. Itachi desperately fought back against his child's insidious technique. Reality sloughed away, a domain of deathly energies appearing in its place. A celestial Sharingan appeared in the darkening sky above, glaring down at him. A heavy mist rose from the ground, weighing down his chakra. All around him, a forest of skeletal trees sprouted. The ground beneath his feet grew slick and crystalline, and the shadows lingering about swelled until they reached grossly exaggerated proportions.

“You resist,” Sasuke whispered, his gaze mocking. Itachi could feel his will weakening; the aura of death lingering just behind his soul like an excluded ghost desperate for company.

“Amaterasu!” Itachi watched as his child flickered away. The boy's expression was twisted in a rictus of pain as he looked down at his burning arm, before unhesitantly severing it.

Itachi's mind was filled with white noise.

...What have I done? He thought to himself as he stared at his crippled child.

Time passed.

The teen had not grown; a traitor now. Sasuke, bearer of his hopes and dreams, had taken the Uchiha name he killed and died for, and dragged it through the muck.

Konoha lay in ruins.

Brought to its knees by Sasuke...

His wayward child.