Sime started; perhaps Cairn's story was not a matter of imagination after all.
"There is someone here, dressed like that, I believe," he replied, with affected carelessness. "He seems to have frightened several people. Any idea who he is?"
"My dear chap!" cried the Colonel, "I have been searching the place for him! But I have never once set eyes upon him. I was about to ask if _you_ knew anything about it!"
Sime returned to the table where Cairn was sitting. The latter seemed to have recovered somewhat; but he looked far from well. Sime stared at him critically.
"I should turn in," he said, "if I were you. _Khamsîn_ is playing the deuce with people. I only hope it does not justify its name and blow for fifty days."
"Have you seen the man in the mask!" asked Cairn.
"No," replied Sime, "but he's here alright; others have seen him."
Cairn stood up rather unsteadily, and with Sime made his way through the moving crowd to the stairs. The band was still playing, but the cloud of gloom which had settled upon the place, refused to be dissipated.
"Good-night, Cairn," said Sime, "see you in the morning."
Robert Cairn, with aching head and a growing sensation of nausea, paused on the landing, looking down into the court below. He could not disguise from himself that he felt ill, not nervously ill as in London, but physically sick. This superheated air was difficult to breathe; it seemed to rise in waves from below.
Then, from a weary glancing at the figures beneath him, his attitude changed to one of tense watching.
A man, wearing the crocodile mask of Set, stood by a huge urn containing a palm, looking up to the landing!
Cairn's weakness left him, and in its place came an indescribable anger, a longing to drive his fist into that grinning mask. He turned and ran lightly down the stairs, conscious of a sudden glow of energy. Reaching the floor, he saw the mask making across the hall, in the direction of the outer door. As rapidly as possible, for he could not run, without attracting undesirable attention, Cairn followed. The figure of Set passed out on to the terrace, but when Cairn in turn swung open the door, his quarry had vanished.
Then, in an _arabîyeh_ just driving off, he detected the hideous mask. Hatless as he was, he ran down the steps and threw himself into another. The carriage-controller was in attendance, and Cairn rapidly told him to instruct the driver to follow the _arabîyeh_ which had just left. The man lashed up his horses, turned the carriage, and went galloping on after the retreating figure. Past the Esbekîya Gardens they went, through several narrow streets, and on to the quarter of the Mûski. Time after time he thought he had lost the carriage ahead, but his own driver's knowledge of the tortuous streets enabled him always to overtake it again. They went rocking along lanes so narrow that with outstretched arms one could almost have touched the walls on either side; past empty shops and unlighted houses. Cairn had not the remotest idea of his whereabouts, save that he was evidently in the district of the bazaars. A right-angled corner was abruptly negotiated--and there, ahead of him, stood the pursued vehicle! The driver was turning his horses around, to return; his fare was disappearing from sight into the black shadows of a narrow alley on the left.