A man is found lying face down, dead in the middle of a vast desert.
There are no footprints or tracks anywhere around him for miles.
On his back is a pack, a full canteen of water hangs at his side, and he is clutching a small metal ring in his hand.
How did he die?
He jumped from an airplane and his parachute failed to open. The pack on his back was the parachute, and the ring in his hand was the pull cord.
In classic mythology, there is the story of the Sphinx, a monster with the body of a lion and the upper part of a woman.
The Sphinx lay crouched on the top of a rock along the highroad to the city of Thebes, and stopped all travellers passing by, proposing to them a riddle.
Those who failed to answer the riddle correctly were killed.
This is the riddle the Sphinx asked the travellers: "What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?"
This is part of the story of Oedipus, who replied to the Sphinx, "Man, who in childhood creeps on hands and knees, in manhood walks erect, and in old age with the aid of a staff."
Morning, day and night are representative of the stages of life.
The Sphinx was so mortified at the solving of her riddle that she cast herself down from the rock and perished.
