Main Fissure and Tracks
The rail for the mine carts runs along a curving path that follows the natural opening of the fissure in the rock - branches are carved every couple of meters, splitting off from the wider, higher fissure in all directions. After passing beyond the initial larger chamber, the mine devolves rapidly into a maze-like series of tunnels.
Once the party progresses about half-way through the mine - whether they are at the top of the arching main passage where the tracks follow the fissure, or have broken off into side passages, the Catch & Kill encounter should begin.