"Guess we've outstayed our welcome!" confided an American lady to Sime. "Egypt wants to drive us all home now."
"Possibly," he replied with a smile. "The season has run very late, this year, and so this sort of thing is more or less to be expected."
The orchestra struck up a lively one-step, and a few of the more enthusiastic dancers accepted the invitation, but the bulk of the company thronged around the edge of the floor, acting as spectators.
Cairn and Sime wedged a way through the heterogeneous crowd to the American Bar.
"A 'tango,'" explained Sime, "is a new kind of cocktail sacred to this buffet. Try it. It will either kill you or cure you."
"I must confess that I need bucking up a bit," he said: "that confounded sand seems to have got me by the throat."
Sime briskly gave his orders to the bar attendant.
"You know," pursued Cairn, "I cannot get out of my head the idea that there was someone wearing a crocodile mask in the garden a while ago."
"Look here," growled Sime, studying the operations of the cocktail manufacturer, "suppose there were--what about it?"
"Well, it's odd that nobody else saw him."
"I suppose it hasn't occurred to you that the fellow might have removed his mask?"
"I don't think so," he declared; "I haven't seen him anywhere in the hotel."
"Seen him?" Sime turned his dull gaze upon the speaker. "How should you know him?"
Cairn raised his hand to his forehead in an oddly helpless way.
"No, of course not--it's very extraordinary."
They took their seats at a small table, and in mutual silence loaded and lighted their pipes. Sime, in common with many young and enthusiastic medical men, had theories--theories of that revolutionary sort which only harsh experience can shatter. Secretly he was disposed to ascribe all the ills to which flesh is heir primarily to a disordered nervous system. It was evident that Cairn's mind persistently ran along a particular groove; something lay back of all this erratic talk; he had clearly invested the Mask of Set with a curious individuality.
"I gather that you had a stiff bout of it in London?" Sime said suddenly.
"Beastly stiff. There is a lot of sound reason in your nervous theory, Sime. It was touch and go with me for days, I am told; yet, pathologically, I was a hale man. That would seem to show how nerves can kill. Just a series of shocks--horrors--one piled upon another, did as much for me as influenza, pneumonia, and two or three other ailments together could have done."