Tubby sometimes knew better than he made out, and perhaps Andy was wise not to pursue the subject any further; he had been “stung” before, when attempting to take advantage of a “break” on the part of amiable Tubby.

“After this,” Rob was telling them, “be careful not to talk so loud. We don’t know which trail those men may take in passing across the border; but if they heard us speaking they would become suspicious at once. You must know that the very desperate character of their work would make them think everybody’s hand was raised against them; and the chances are they’d feel inclined to pounce on us, and at least make us prisoners.”

“Oh, that must never be!” said Donald, with deep feeling. “If they kept us fra warnin’ the bridge guards, ye ken, the whole thing wud be in the soup.”

After that they all fell silent, and the forward progress was carried out as so many ghostly specters in a country churchyard might stalk about at the hour of twelve, if, indeed, such visitors from the other world ever do visit this one.

For one thing the path actually seemed to be growing easier now, Tubby thought. At least he did not meet with so many obstacles to his progress, and could thank his lucky stars on this account. He really believed every square inch of his stout limbs below his knees must by now show signs of having come in rough contact with stumps, logs, rocks and all other manner of things. Indeed, Tubby had already made up his mind to apply in person to Rob for a portion of that healing salve, when a fitting opportunity arrived and their mission had been carried through successfully.

All of them listened anxiously as they went along. If a bird or a squirrel moved amidst the pine needles or the branches of a neighboring tree the sound, faint though it might be, gave them a corresponding thrill, because their nerves were all on edge, so to speak. Had a deer, lying in a thicket, suddenly bounded away with a crash of the undergrowth, Tubby feared he would faint, it was apt to give him such a terrible shock.

But there was no such alarm, and they were making steady progress all the while. Rob, as a rule, mapped out his plan of campaign beforehand, and he would have done so in this particular case also, only he considered that the honor of giving the warning should belong to Donald. The devoted Canadian boy had made a gallant attempt to carry the news of his terrible discovery to those in charge of the bridge’s safety; he had suffered all manner of pain and hardship in the effort, and it seemed only fair that he should reap most of the reward.

Besides, Donald knew the lay of the land in the vicinity of the bridge. Without his assistance as pilot to the expedition they might have strayed from the path and lost so much valuable time that even though they eventually arrived it would be only in time to hear the stunning report that would tell them the bridge was destroyed, and that the trainload of munitions had gone down into the gulf, a twisted mass of wreckage.

Tubby had conceived a new and somewhat alarming thought, and he wished that Rob had not placed that embargo on speech, for he wanted to ask a question very much. As it was, he had to take it out in looking anxiously upward every time they happened to be in an open bit of ground, where one could glimpse the clear heavens overhead, by straining the muscles of his neck terribly.

The fact of the matter was, Tubby had remembered about the aeroplane which all of them had so earnestly watched on that other day, when it sped across the line, descending low enough for the pilot to snap off a series of pictures of the ground below, together with the long railway bridge, and then once more scuttled away, heading for the American side of the border. He wondered whether those who meant to undertake the destruction of the bridge would come again in an aerial craft, and try to drop bombs upon the bridge at the moment the freight from the west was approaching the trestle.