FILE NO. 0014-D · STATUS: CATALOGUED, UNEXPLAINED

Three separate expeditions, three separate regions, one detail none of us shared with each other until comparing notes at a supply drop: a low hum recorded from bare rock, always at 6.2 kHz, always fading exactly when we stopped listening for it — never before.

Stone doesn't hum. Ours does.

We ran the recordings against every known mineral resonance on file. No match. The closest comparison in our archive is, unhelpfully, silence.

If you've caught something similar, log the frequency and the exact moment you noticed it fade. The timing might matter more than the sound itself.

◎ CROSS-REFERENCING IN PROGRESS.