She kept her promise so well that for an industrious hour Lidgerwood scarcely realized that he was not alone.  For the greater part of the interval the sight-seers were out on the rear platform, listening to Miss Brewster’s stories of the Red Desert.  When she had repeated all she had ever heard, she began to invent; and she was in the midst of one of the most blood-curdling of the inventions when Lidgerwood, having worked through his bunch of papers, opened the door and joined the platform party.  Miss Brewster’s animation died out and her voice trailed away into—­“and that’s all; I don’t know the rest of it.”

Lidgerwood’s laugh was as hearty as Van Lew’s or the collegian’s.

“Please go on,” he teased.  Then quoting her:  “’And after they had shot up all the peaceable people in the town, they fell to killing each other, and’—­Don’t let me spoil the dramatic conclusion.”

“You are the dramatic conclusion to that story,” retorted Miss Brewster, reproachfully.  Whereupon she immediately wrenched the conversation aside into a new channel by asking how far it was to the canyon portal.

“Only a mile or two now,” was Lidgerwood’s rejoinder.  “Williams has been making good time.”  And two minutes later the one-car train, with the foaming torrent of the Timanyoni for its pathfinder, plunged between the narrow walls of the upper canyon, and the race down the grade of the crooked water-trail through the heart of the mountains began.

There was little chance for speech, even if the overawing grandeurs of the stupendous crevice, seen in their most impressive presentment as alternating vistas of stark, moonlighted crags and gulches and depths of blackest shadow, had encouraged it.  The hiss and whistle of the air-brakes, the harsh, sustained note of the shrieking wheel-flanges shearing the inner edges of the railheads on the curves, and the stuttering roar of the 266’s safety-valve were continuous; a deafening medley of sounds multiplied a hundred-fold by the demoniac laughter of the echoes.

Miss Carolyn clung to the platform hand-rail, and once Lidgerwood thought he surprised Van Lew with his arm about her; thought it, and immediately concluded that he was mistaken.  Miriam Holcombe had the opposite corner of the platform, and Jefferis was making it his business to see to it that she was not entirely crushed by the grandeurs.

Miss Brewster, steadying herself by the knob of the closed door, was not overawed; she had seen Rocky Mountain canyons at their best and their worst, many times before.  But excitement, and the relaxing of the conventional leash that accompanies it, roused the spirit of daring mockery which was never wholly beyond call in Miss Brewster’s mental processes.  With her lips to Lidgerwood’s ear she said:  “Tell me, Howard; how soon should a chaperon begin to make a diversion?  I’m only an apprentice, you know.  Does it occur to you that these young persons need to be shocked into a better appreciation of the conventions?”