A small research team went down below the surface to find out what secret the world's deepest borehole was hiding. What they have found turned out to be the greatest threat in history. And t... Read allA small research team went down below the surface to find out what secret the world's deepest borehole was hiding. What they have found turned out to be the greatest threat in history. And the future of humanity is in their hands.A small research team went down below the surface to find out what secret the world's deepest borehole was hiding. What they have found turned out to be the greatest threat in history. And the future of humanity is in their hands.