In the underground base beneath Upper Capital stood a top-secret prison cell.
Pale gray soundproofing covered both sides of the passage, with cool white lights recessed into the ceiling every five meters.
Beyond two blast doors and a station for iris scans and palm-print verification, the innermost cell appeared at the end of the corridor.
The cell was enclosed by high-strength, multilayer composite bulletproof glass, visibly more than twenty centimeters thick.
Sealing talismans densely covered the inner surfaces of all four walls, each paper overlapping the corners of another.
Black technique markings stood out clearly beneath the cool white lights, crisscrossing into several overlapping layers of sealing arrays.
Fine sealing patterns were also embedded along the seams where the ceiling and floor met the walls, linking with the talismans to form a three-dimensional sealing structure.
Kushina Uzumaki and Minato had developed this sealing array together.
At the center of the cell, Uchiha Madara sat cross-legged with his eyes closed, his posture upright, his back straight, and his hands resting naturally on his knees.
His breathing was steady and slow, as though he were meditating. The fabric over his back bulged slightly, and the markings of the Eight Trigrams Seal showed through it as dark outlines.
Like a brand burned deep into his skin, the seal spread outward from between his shoulder blades, covering almost his entire back, with black tadpole-like markings arranged evenly along either side of his spine.
In the monitoring area outside the cell, three personnel took turns keeping watch before a row of screens, their eyes continuously tracking every angle of the cell.
At regular intervals, someone adjusted a camera angle to ensure that even the slightest movement inside the cell was recorded.
The monitors continuously displayed heart rate, body temperature, blood pressure, respiratory rate, and other