The Resonance of the Deep-Iron Gate

The chamber is a natural limestone cathedral where the air vibrates with a persistent, low-frequency thrumming. At the far end stands a massive basalt door, its surface webbed with veins of translucent violet quartz that pulse in rhythm with the cavern's heartbeat. To the left of the door, a heavy iron rack holds five vertical metal rods of varying lengths, ranging from a few inches to three feet. The scent of ozone and wet slate is thick here, and every footstep produces an echo that seems to linger a second too long in the humid air.