On a remote peninsula in north-west Russia, scientists have spent decades drilling down towards the center of the earth. At over 40,000 feet, their borehole is the deepest that man has ever gone. Then, however, something unexpected happens, and the researchers are forced to seal up their experiment for good.
Ever since the first artificial satellite was sent into space in 1957, humans have been infatuated with discovering the secrets of the stars. And now, with the help of global space agencies and private companies, we know more about the universe than ever before. But as we continue to stare skywards in wonder, are we overlooking another equally mysterious world back on Earth?