He was nearing the vortex. The spiral motion became quicker. An irresistible force was dragging him down. Suddenly Denbigh threw up his arms. He was physically played out. Like an arrow he shot into the pit in the centre of that mass of whirling water. The blaze of the African sun gave place to intense darkness. He held his breath, until his lungs seemed to be on the point of bursting. As rapidly as he had gone down the sub was shot to the surface. Again he was within the range of the whirlpool, for its centre, instead of being stationary, was moving in an ellipse. Unable even to struggle, Denbigh was again sucked down. This time, incapable of holding his breath, he swallowed a quantity of water. The pressure on his chest was excruciating. Then torture gave place to a strange calmness. On an instant, recollections of practically the whole of his past life flashed across his mind. The mental pictures faded away and all became blank. CHAPTER XVII A Bid for Freedom When Denbigh opened his eyes he found himself in the now familiar cabin on board the _Pelikan_. There were several people in the limited space. He did not feel any interest in them. They irritated him. He wanted to sleep. Gradually it dawned upon him that he had a narrow escape. Then he remembered that O'Hara was with him when he was swept off the side of the _Myra_. "You there, Pat?" he asked, half afraid to put the question in case his chum was gone. "Sure," replied a deep voice from the opposite bunk. Denbigh attempted to sit up. He felt horribly sick. His head was whirling. It reminded him very forcibly and unpleasantly of his spiral flight around the vortex of the whirlpool. "Lie still, Mr. Denbigh," said Captain Pennington. "You'll be fit all in good time." "All right," agreed the sub. He was not in a fit state to do otherwise. "Where is the _Pelikan_ now?" The skipper of the _Myra_ lowered his voice. "Properly trapped. She cannot go another fifty yards up the river. We've spoilt her little game." "Good business," murmured Denbigh, and turning on his side he fell asleep. His escape was little short of miraculous. It was owing to the fact that he wore his solar topee fastened by a strong "chin-stay". The air-space between the double thickness of the sun-helmet possessed sufficient buoyancy to bring him to the surface, after being twice taken down by the whirlpool. A few minutes previous to the disaster, the bore had exhausted itself at a point ten miles up the river, and the "rebound" had made itself felt just at the time when Denbigh made his second involuntary dive. The sudden slackening of the full force of the flood-tide had caused the whirlpool to cease, with the result that the sub floated unconscious on the surface of the river, when he was picked up by the _Pelikan's_ whaler. O'Hara, Captain Pennington, and Armstrong had been more fortunate, for they had been swept clear of the influence of the eddy.