Transcript (en)

270 meters underwater, a camera on this diver's helmet is recording the last minutes of his life. He will never swim out of here. And yet four days later, he comes back up, bringing with him the man he went down to get. This is Bushman's Hole in South Africa, a pond the size of a swimming pool, and below it, one of the deepest flooded caves on earth. In October 2004, Dave Shaw, an Australian airline pilot, reaches its floor, and his light falls on a body. It is Dion Dreyer, who blacked out here 10 years earlier, age 20, and sank out of reach. Shaw cannot lift him out of the mud, so he ties his guideline to the body and promises Dion's parents, I will fetch your son. On January 8, 2005, he goes back with a plan. Five minutes at the bottom to bag the body, a handover to his friend Don Shirley at 220 meters, then almost 12 hours of slow ascent, because rising faster would kill him. He drops down the line, and 12 minutes later, he kneels beside the body. Everyone expected it to stay pinned in the mud, but it comes loose and floats, rolling in front of him as he fights with the bag. He has let go of his lamp to use both hands, and the guideline he tied here in October drifts around it He is working too hard and at this depth his lungs can no longer clear the carbon dioxide After five minutes he turns to leave right on time and does not get far The line has caught his lamp and its other end is tied to the body. He has shears in his hand, but he never cuts it. His breathing gets faster and faster, and then there is silence. Thirteen minutes behind him comes Don Shirley, and from 150 meters, he sees Shaw's light far below. It is not moving, and no bubbles are rising. He goes after his friend, deeper than he has ever been until at about 250 meters the pressure crushes the computer that controls his breathing gas. He turns around and on a slate he writes Dave not coming back. His way up takes more than 12 hours and on the way a bubble of helium in his inner ear sends the cave spinning. He loses the line catches it again in his light and comes out alive with his balance damage for good. Shaw had told his team if something goes wrong leave me down there but four days later two divers raise the main line to collect the tank still hanging on it. It pulls on the guidelines still caught on Shaw's lamp. The gas in his suit expands, and he rises, faster and faster, to the roof of the cave, 20 meters below the surface, and in the line beneath him hangs Dion Dreyer. Dave Shaw did not come back alive, but he kept his promise, and the camera was still on his helmet. Its tape shows what happened in those last minutes, 270 meters down.