The archway opened, a vortex of shimmering particles spiraling inward. Beyond it lay a cavern, illuminated by bioluminescent flora that clung to walls of the same black stone. In the center of the cavern floated a , no larger than a basketball, suspended in a column of anti‑gravity field. The sphere emitted the same harmonic tones, but now they resonated in three dimensions, filling the cavern with a choir of sound.

Milo’s optical sensors zoomed in on a faint crack at the tower’s base. “Structural anomaly detected. Probability of breach: 12% if resonance continues.”

Mara gasped. “It’s a , a backup of a lost civilization.”

“Did anyone else feel that?” Nara asked, her eyes wide.