Between the Devil and the Deep

Deep underwater lurks a mysterious man-made illness. It has gone by many names over the years - Satan's disease, diver's palsy, the chokes - but today, medics call it decompression sickness. You know it as the bends. That's the devil British diver Martin Robson faces each time he plunges beneath the surface.

In the winter of 2012, Robson was part of an expedition to Blue Lake in the mountainous borderlands of southern Russia, which sought to find a submerged cave system never seen by the human eye. On the final day of the expedition, Robson dived deeper into the lake than anyone had before, and as he returned from the bottom disaster struck: just 75 feet down, he was ambushed by the bends. Bubbles exploded in his spine and he was paralysed below the waist.

Robson knew that if he went up to the surface he would probably die before help arrived. Instead, he gambled on an underwater practice most doctors believe is a suicidal act. Trapped by the lake's icebox grip, unable to move his legs, and with a dwindli.