| Goldfield's Beatrix gold mine lies a few hours outside of Johannesburg, South Africa, in one of the richest gold fields in the world. It extends more than two kilometres underground. The mine has a workforce of about 10,500 employees and produces 400k oz of gold per year. But recently, something living came up with the gold, a creature that has been named after Mephisto, the Devil from the Faust legend. This seems like something from a tale, where miners dig 'too deep' and release an unspeakable evil. |  Fortunately, the creature that lurks in the Beatrix mine – Halicephalobus mephisto – is barely half a millimetre long. |
 In the classic German Faustian legend, Mephistopheles promises Faust that he will give him everything that he desires, but in exchange, Faust will then have to serve the devil in Hell. | It’s no demon, but it is a surprising find. It’s an animal that lives where no other animals were thought to exist, in the rocky underworld known as the 'deep subsurface'. To H.mephisto and the other nematodes, the subterranean world is an all you can eat buffet. They feed on bacteria and other microbes that grow in rich mats on the rocky surface. There are up to a trillion such cells for every one nematode, a feast that could keep H.mephisto going for around 30,000 years. There’s no risk of starving in the deep subsurface. |  |
