The Whetstone's Grate and the Bedrock Pulse

In the quiet dimness of the secondary maintenance shaft, the foul-smelling air felt marginally lighter as Lyra's distant pressure codes began to take effect through the bedrock. Sitting upon a damp crate just feet from the braced access hatch, Oren methodically stroked a coarse oilstone against the edge of his shortsword. The local subterranean scout had clothes torn and caked in dried mud from crawling through service chutes, and the rhythmic scraping noise of the steel blended with the low, subterranean thrum vibrating through the stone floor.

Bram paused briefly from checking the heavy iron wedges to wipe condensation from his brow, listening intently to the muffled sounds of the predator swarm scratching lazily against the outer plates. The metallic screech echoing softly through the narrow corridor carried a sharp, piercing pitch that cut cleanly through the damp air.

Slumped against the damp masonry near the secured hatch, Thalia opened her eyes at the sound of the blade. Struggling under the crushing weight of her persistent mana depletion and a debilitating migraine, she quietly urged Oren to mute the sharpening, whispering a desperate warning that even small metallic frequencies might travel through the bedrock and draw the sightless predators right back to their trembling barricade. As Oren lowered the stone and the shaft fell back into a tense, breathless silence, the distant, volatile rumble of the lower vaults continued to pulse like a slow heartbeat in the dark.