“You have a marvellous collection of tall stories,” said Arthur. “I’m afraid I should want better proof that these particular snakes are poisonous.”

Oliver turned to the charmer and spoke to him in Arabic. Then he answered Arthur.

“The man has a horned viper, cerastes is the name under which you gentlemen of science know it, and it is the most deadly of all Egyptian snakes. It is commonly known as Cleopatra’s Asp, for that is the serpent which was brought in a basket of figs to the paramour of Caesar in order that she might not endure the triumph of Augustus.”

“What are you going to do?” asked Susie.

He smiled but did not answer. He stepped forward to the centre of the tent and fell on his knees. He uttered Arabic words, which Dr. Porhoët translated to the others.

“O viper, I adjure you, by the great God who is all-powerful, to come forth. You are but a snake, and God is greater than all snakes. Obey my call and come.”

A tremor went through the goatskin bag, and in a moment a head was protruded. A lithe body wriggled out. It was a snake of light grey colour, and over each eye was a horn. It lay slightly curled.

“Do you recognize it?” said Oliver in a low voice to the doctor.

“I do.”

The charmer sat motionless, and the woman in the dim background ceased her weird rubbing of the drum. Haddo seized the snake and opened its mouth. Immediately it fastened on his hand, and the reptile teeth went deep into his flesh. Arthur watched him for signs of pain, but he did not wince. The writhing snake dangled from his hand. He repeated a sentence in Arabic, and, with the peculiar suddenness of a drop of water falling from a roof, the snake fell to the ground. The blood flowed freely. Haddo spat upon the bleeding place three times, muttering words they could not hear, and three times he rubbed the wound with his fingers. The bleeding stopped. He stretched out his hand for Arthur to look at.