MEMBER REVIEW: This is a Nova program, and very cutting edge in life sciences. You go into caves that are not on your vacation itinerary because they are lethal due to various noxious gases in them. You see giant calcite, snotites, and weird biology. These scientists are working on life forms you do not see every day. They live in sulfuric acid, methane, and other deadly gases and compounds. These might be the descendants of ancient extremophiles. They also explore cave formation, and it seeems some caves were created through chemical processes, not just the usual water erosion. This is cutting edge science on many levels. A must-see video. Description: It is pitch black, toxic gases bubble up from deep below, sulfuric acid drips from above, and carbon monoxide fills the air. It is not a scene from a horror movie, but the interior of a beautiful, but treacherous, cave. Explore the beauty and danger found in some of the most exotic caves of the world as NOVA explores dark recesses, off limits to all except researchers.