Elara froze. The Deep had ghosts, the old-timers said. Echoes of miners lost in the crushing black. But the seismic needle was jumping frantically now. There was mass on the other side. Flesh and blood.

Thus, the word embodies a metaphor: a rabbit is, essentially, a “tunnel-digger.”

The word cuniculus is a fascinating example of linguistic and biological convergence. Depending on the context—zoology, archaeology, or anatomy—it refers either to a furry mammal, an ancient military tunnel, or a small groove in the brain.

Here, the tunnels were not polished. They were raw, jagged wounds in the earth. This was the Cuniculus in its primal state.

That was the official name for the network. The Great Burrow. To the citizens living in the sprawling, retrofitted ant-hill cities of the Deep, the Cuniculus was an artery. To Elara, it was a living thing. It breathed with the draft of ventilation fans; it pulsed with the rumble of supply trains.

As the doors sealed shut behind them, Elara placed her hand on the cold metal. She felt a faint vibration, not like a machine, but like a heartbeat.