This is a short 18 minute documentary from my perspective as a caver and cinematographer. I wanted to convey the feelings of being deep underground in the vertical caves of northern Mexico, and show the scientists and explorers who find value in their study. Narration is by project leader and geologist Peter Sprouse. Produced in conjunction with the Association for Mexican Cave Studies, a non-profit project of the National Speleological Society. I had the sensitivity of the 5DmkII camera on my side, as I was able to shoot the underground scenes using only headlamp illumination. In my opinion, the result is a more accurate feel for how we cavers experience the cave, Our field of view is narrowed, and the lights of our buddies create texture and beautiful highlights. That extra sensitivity of a few hundred ASA gave me a finished product with a very respectable noise level. I had a lot of fun shooting this, and I hope you enjoy it.