“Never dig deeper than you need.”
Nobody remembered why.
The Night
The Heartbeat put out every lamp, and the deep came up. The moles fled to the surface and built New Burrow. It was meant to be temporary. It became home.
The Seals
Lamp Seals keep the old roads shut. Only a light strong enough may pass.
The Heartbeat
One morning the ground shakes and a sealed tunnel collapses. Behind it: a symbol from the oldest relics, and a sound. Then a wounded monster climbs out. It does not attack. It runs.
“How deep can it be?”
The eldest answers: “We don't know.”