Discovery tonight airs new extreme reality show Darkness — with the premiere seeing three men spend six days in snake-infested caves, with no light.
Night-vision cameras mean only viewers can see what the contestants end up doing as they feel their way around the Cave of the Seven Serpents.
The aim is for them to find the exit to the treacherous cave system, which is buried under the Ozark Mountains in Missouri.
The entire escape bid takes place in complete darkness as they feel their way around the cavernous network.
Falls and the threat of injury as they move around trying to find a way out, with snakes crawling over them — and just edible earthworms as a tasty treat.
A second episode, airing tomorrow, Thursday August 3, sees a Marine Reserve, an engineer and a Navy survival instructor left in an abandoned Cold War fallout shelter 240ft underneath the Mojave Desert.
In the episode, titled Forgotten Tomb, they have to find the way out while struggling with hallucations, the effects of isolation, and the threat of starvation.
What happens to your mind after long periods in complete darkness? Find out in the video below:
Darkness airs tonight, Wednesday August 2 and tomorrow, Thursday August 3, at 10/9c on Discovery.