Cairnveil Swarm

Jessa stepped onto what looked like a stair and found air.

We'd taken the motes for pale moths until one landed on a cairn and became a blank mask. Hundreds settled over the stones, hiding their cuts and changing the stack's shape. When they rose, a road I knew ran north appeared to turn east. Around the lantern, white motes laid borrowed shadows over gaps and cliffs.

We scattered the top stones from every cairn we could reach. Without trusted shapes to hold, the masks lost their common face and fled into the scree as sparks.

It changes what the eye believes is arranged before it, rather than blinding it. The swarm circles ahead and occupies route markers or broken stair edges. One landmark changes, then another after the group acts on the first mistake. Threatened, the masks make a large face in the air with overlapping false ledges around it.

Individual spirits are fragile, but striking the cloud scatters it toward more landmarks. Temporarily lowering cairns and covering signs deprives it of reliable shapes. Use rope, the slope, or running water to navigate until it disperses.