Briefly, the plan was as follows, at least so far as it concerned England.  The volor was to approach Palestine from the direction of the Mediterranean, observing to get into touch with France on her left and Spain on her right within ten miles of the eastern end of Crete.  The approximate hour was fixed at twenty-three (eastern time).  At this point she was to show her night signal, a scarlet line on a white field; and in the event of her failing to observe her neighbours was to circle at that point, at a height of eight hundred feet, until either the two were sighted or further instructions were received.  For the purpose of dealing with emergencies, the President’s car, which would finally make its entrance from the south, was to be accompanied by an aide-de-camp capable of moving at a very high speed, whose signals were to be taken as Felsenburgh’s own.

So soon as the circle was completed, having Esdraelon as its centre with a radius of five hundred and forty miles, the volors were to advance, dropping gradually to within five hundred feet of sea-level, and diminishing their distance one from another from the twenty-five miles or so at which they would first find themselves, until they were as near as safety allowed.  In this manner the advance at a pace of fifty miles an hour from the moment that the circle was arranged would bring them within sight of Nazareth at about nine o’clock on the Sunday morning.

* * * * *

The guard came up to the four as they stood there silent.

“We are ready, gentlemen,” he said.

“What do you think of the weather?” asked Snowford abruptly.

The guard pursed his lips.

“A little thunder, I expect, sir,” he said.

Oliver looked at him curiously.

“No more than that?” he asked.

“I should say a storm, sir,” observed the guard shortly.

Snowford turned towards the gangway.

“Well, we had best be off:  we can lose time further on, if we wish.”

It was about five minutes more before all was ready.  From the stern of the boat came a faint smell of cooking, for breakfast would be served immediately, and a white-capped cook protruded his head for an instant, to question the guard.  The four sat down in the gorgeous saloon in the bows; Oliver silent by himself, the other three talking in low voices together.  Once more the guard passed through to his compartment at the prow, glancing as he went to see that all were seated; and an instant later came the clang of the signal.  Then through all the length of the boat—­for she was the fastest ship that England possessed—­passed the thrill of the propeller beginning to work up speed; and simultaneously Oliver, staring sideways through the plate-glass window, saw the rail drop away, and the long line of London, pale beneath the tinged sky, surge up suddenly.  He caught a glimpse of a little group of persons staring up from below, and they, too, dropped in a great swirl, and vanished.  Then, with a flash of dusty green, the Common bad vanished, and a pavement of house-roofs began to stream beneath, the long lines of streets on this side and that turning like spokes of a gigantic wheel; once more this pavement thinned, showing green again as between infrequently laid cobble-stones; then they, too, were gone, and the country was open beneath.