The bottom was not a floor. It was a mirror.

Leo looked down and saw not his reflection, but a younger version of himself—age ten, the year the选拔 trials had taken his brother. The boy stared up with hollow eyes and whispered, "You left him."

"Remember the objective: retrieve one intact singing glass fragment and ascend. No deviations. The pressure at depth will fog your cognitive clarity inside thirty seconds. You will feel euphoric. You will want to stay. That’s the crystal singing to your nervous system. Ignore it."

For the first three kilometers, the shaft was wide as a cathedral. Stalactites of singing glass glowed faintly amber, vibrating at a frequency he felt in his molars. His suit's audio pickups translated the hum into a low, wordless choir. Stay, they seemed to say. Listen.