The chamber dissolved behind them, fragments of the Heart scattering like ash. Mark and Lyra stumbled through the glowing exit, emerging into Numina's central square. The sun was gone, replaced by a sky of swirling numbers, as if the Tower's collapse had torn the fabric of reality. Citizens gasped, pointing at the sky, their whispers sharp with fear.
Mark's Seal pulsed, heavy with the Numen of their final answer—π²/6. Lyra's hand was still in his, her grip tight. "We broke it," she said, but her voice wavered. "So why doesn't it feel over?"
The ground trembled, and a shadow rose from the Tower's ruins—a massive figure, its form a mosaic of equations, its eyes burning with the scholar's light. "You shattered the Heart," it roared, "but the Tower endures. Face its final judgment."
A problem blazed across the sky, its symbols vast:
Solve the matrix:
[2 1] [x] = [5]
[1 2] [y] = [7]
Mark's heart raced. A 2x2 matrix. Use the inverse. Determinant: 2×2 – 1×1 = 3. Inverse: (1/3)[[2 -1], [-1 2]]. Multiply by [5, 7]: x = (2×5 + (-1)×7)/3 = 1, y = ((-1)×5 + 2×7)/3 = 3.
"x = 1, y = 3," he said.
Lyra nodded, her own calculation matching. The shadow roared, but the sky's numbers dimmed, Numen flooding their Seals. The figure began to dissolve, but it laughed—a sound that chilled Mark's blood. "You wield power, but Numina will demand it back. The cycle continues."
The shadow vanished, and the sky cleared. The crowd cheered, calling Mark's name, but Lyra's face was grim. "The Tower's gone," she said, "but its equations are in us now. We're not free."
Mark looked at his Seal, still glowing. She was right. The Numen felt alive, restless. He gripped his chalk. "Then we keep solving. Together."
Lyra's eyes softened, just for a moment. "Together."