Just as he was rising to leave he shoved a tiny strip of paper across the table to me with a sidelong glance at Foulet. "Another roof-top," I read scrawled in pencil. "If you like, meet me at the flying field before dawn." If I liked! I shoved the paper across to Foulet who read it and carelessly twisted it into a spill to light his cigar. But his hand shook ever so slightly.
Needless to say we went to the flying field shortly after midnight. Bruce was there, pacing up and down restlessly. Near him was a huge tri-motored biplane, its motor humming in readiness.
"I've put a man on the trail in my place," Brice told us briefly. "Somebody else is going to lose the scent on a roof-top—and I'm going to watch."
We settled to our wait. To me it seemed absurdly hopeless. The flying field was on a slight rise. Below us spread the dark shadow that was Constantinople. There was no moon to give it form and substance—it was just a lake of deeper darkness, a spreading mass of silent roof-tops and minarets. How did Brice expect to see his quarry escape? Suppose he fled during the night? And even with daylight—
The first streaks of dawn found us still waiting, our ears strained for the hum of an airplane motor. But hardly had the golden rim of the sun appeared over the horizon when it came. It came from the east—straight out of the golden glory of the sun. Nearer and nearer it came; an airplane—alone.
"It hasn't got the glider," muttered Foulet and his tone was tinged with disappointment. But hardly had he spoken when, from one of the myriad roof-tops below us, rose a swift streak of shadow. So fast it flew, with such unbelievable speed, that to our eyes it was little more than a blur; but—
"The glider!" Brice gasped. "My God! How did he do it?" We stared, silent with amazement. The airplane, that only a second before had flown alone, now was towing a glider—a glider that had arisen, as if by magic, from the housetops!
Another instant and we had piled into the cockpit of the tri-motored plane and were off on our pursuit. That pursuit that led us on and on till, as the sun sank behind us, we found ourselves above the illimitable, tawny wastes of the great Arabian Desert.
And now—what? All day long, as I have said, the plane we were pursuing had maintained, but never increased, the distance between us. Each hour had brought us renewed hope that the next hour would bring capture—or at least some definite clue, some shred of information. But the plane, still towing its glider, had gone on and on, steadily, imperturbably. And we dared not open fire and attempt to bring it down for fear of destroying our one meager chance of following it to its destination.