He drew his son from the room. On the stair:

"You understand?" he asked. "The spirit of Mirza came to him again,
clothed in his wife's body. Lord Lashmore felt the teeth at his
throat, awoke instantly and struck out. As he did so, he turned the
torch upon her, and recognised--his wife! His heart completed the
tragedy, and so--to the laughter of the sorceress--passed the last of
the house of Dhoon."

The cab was waiting. Dr. Cairn gave an address in Piccadilly, and the
two entered. As the cab moved off, the doctor took a revolver from his
pocket, with some loose cartridges, charged the five chambers, and
quietly replaced the weapon in his pocket again.

One of the big doors of the block of chambers was found to be ajar,
and a porter proved to be yet in attendance.

"Mr. Ferrara?" began Dr. Cairn.

"You are five minutes too late, sir," said the man. "He left by motor
at ten past twelve. He's gone abroad, sir."

CHAPTER XI

CAIRO

The exact manner in which mental stress will effect a man's physical
health is often difficult to predict. Robert Cairn was in the pink of
condition at the time that he left Oxford to take up his London
appointment; but the tremendous nervous strain wrought upon him by
this series of events wholly outside the radius of normal things had
broken him up physically, where it might have left unscathed a more
highly strung, though less physically vigorous man.

Those who have passed through a nerve storm such as this which had
laid him low will know that convalescence seems like a welcome
awakening from a dreadful dream. It was indeed in a state between
awaking and dreaming that Robert Cairn took counsel with his
father--the latter more pale than was his wont and somewhat
anxious-eyed--and determined upon an Egyptian rest-cure.

"I have made it all right at the office, Rob," said Dr. Cairn. "In
three weeks or so you will receive instructions at Cairo to write up a
series of local articles. Until then, my boy, complete rest and--don't
worry; above all, don't worry. You and I have passed through a
saturnalia of horror, and you, less inured to horrors than I, have
gone down. I don't wonder."

"Where is Antony Ferrara?"

Dr. Cairn shook his head and his eyes gleamed with a sudden anger.
"For God's sake don't mention his name!" he said. "That topic is
taboo, Rob. I may tell you, however, that he has left England."

In this unreal frame of mind, then, and as one but partly belongi