In the millions of years since oxygen began saturating Earth’s oceans and atmosphere, most organisms have evolved to rely on this gas. However, there are some places where oxygen-averse microorganisms like those from Earth’s earliest days have re-emerged. And one such place is hidden high in the Swiss Alp’s Piora Valley. Nicola Storelli and Daniele Zanzi dive into the depths of Lake Cadagno. Lesson by Nicola Storelli and Daniele Zanzi, directed by Ivana Volda, Thomas Johnson Volda.