The struggle in the isolation ward had lasted several hours.
Outside the window, night lay heavy over Konoha. Most of the village had fallen asleep, but the hospital's top floor remained brightly lit, an island in the darkness. Inside the ward, sweat beaded on the foreheads of Tsunade and the Katsuyu Sage's clone as their senjutsu-infused medical chakra fought the tenacious darkness source for every inch of ground.
Progress was agonizingly slow. Though the purplish-black corruption had been stopped from spreading and a small portion of its outer edge had been purified, its core remained entrenched near Itachi's heart. Like a disease clinging to the bone, it held fast to the source of his life, constantly releasing waves of resistance and retaliation. Every attempt to purify deeper into the core triggered violent, almost self-destructive surges of dark power, causing dangerous fluctuations in Itachi's already faint vital signs.
"No. At this rate, his body will give out before we finish purifying it." Tsunade had no choice but to ease her assault for the moment, her expression grim. She had never encountered anything so difficult. This dark power seemed to possess a malicious intelligence, knowing exactly how to drain both its host and those trying to save him.
"Lady Tsunade," the Katsuyu clone said, a trace of exhaustion in her voice, "this power is extraordinarily dark and ancient in nature. It seems to stand in some kind of opposition to natural energy. Purification alone may not be enough to eradicate it completely while keeping him alive."
Tsunade remained silent. Her gaze swept over the discouraging readings on the monitors, then settled on Itachi's pale, peaceful face. This man, burdened with far too many secrets and sins, now lay as quietly as if he were asleep. Only his tightly knitted brows and the