A third taunting chorus traveled over the desert. But Tom and his friends, in the darkness of the night, could not make out the hors.e.m.e.n nor judge how many there were of them.

"You'd better turn out the camp, Mr. Hawkins," directed Tom in a calmer voice.

The superintendent ran over to where a night engineer almost dozed at his post beside a stationary engine.

Half a minute later a series of shrill blasts rang out over the camp.

Laborers came tumbling out of the tents. Many of them had slept so soundly that even the noise of dynamiting they had regarded only as a part of their dreams. But the whistle meant business.

"Get the torches out, Mr. Rivers," called Tom, as one of the foremen reported on a run.

To Foreman Payson, Harry gave the order to marshal a hundred of the men to remain in and around the camp, alertly watchful.

"That's a good idea," nodded Mr. Ellsworth. "The explosion may be only a trick to, empty the camp, as a prelude to further mischief."

Scores of torches flared in the darkness as the workmen hurried westward. At the head of all went Tom Reade and the general manager.

Less than half a mile away they came upon the scene of mischief.

"It's just what I expected," nodded Tom, as the leading party halted under the flare of the torches. "You see, sir, here was the point of greatest cave and drift in the quicksand. It's where your former engineers found such a mora.s.s of the shifty stuff that they declared the Man-killer never could have its appet.i.te satisfied with dirt. There was a good log and concrete foundation laid down there, and for thirty-six hours the sand had not shifted a particle as far as the eye could discover. Now, look at it!"

Before them the top layer of desert sand had sunk away, revealing a well or sink, one hundred and fifty feet across and the bottom at least forty feet below the general level.

"I always wondered why a suspension bridge wouldn't solve the problem more easily and cheaply than any other construction," muttered Mr.

Ellsworth, after he had gotten over his first indignation.

"To avoid every possibility of lurking quicksand the suspension bridge would have to be more than a mile long," Reade answered. "Beyond, there are other treacherous little patches of quicksand. It would cost the road millions to put up a suspension bridge that would hold.

"A short bridge would look all right and doubtless serve all right, for a while. Then, some fine day, part of the structure would give, and a trainload of pa.s.sengers would be sucked down and out of sight by the shifting sands of the Man-killer."

Mr. Ellsworth turned aside with a shudder.

"I'm glad I'm not an engineer," he said earnestly. "The responsibility for safety of life at this point is all yours, Reade."

"And I'm willing enough to take it, sir, if you don't run trains over the Man-killer until the new roadbed has stood tests that I'll put upon it."

"It'll cost at least ten thousand dollars to repair the mischief that the scoundrels have done to-night," figured Harry Hazelton thoughtfully.

"Then, if we can find out the guilty wretches for certain, we'll see that they earn more than that amount by enforced labor in prison,"'

retorted the general manager grimly.

"Mr. Bell!" called Tom briskly.

"Here, sir," reported the foreman, coming forward..

"Mr. Bell, I wish you'd pick out twenty-one good men. Make the brightest of the lot head of the new force of night watchmen. Place the other twenty under his orders. Your gangs will come into play here later than the others, so I'll let your shift of men have the first chance at night-watchman duty."

"All right, sir," nodded Foreman Bell. "Any further orders?"

"None, except that your watchmen will do their best to guard both the line of roadbed and the camp. Further, tell the night engineer to be sure to have steam up so that he can blow a lot of signals at anytime in the night."

"Very good, sir," and the foreman hurried away.

"I'm disgusted with myself for having been caught in this fashion," Tom admitted to Mr. Ellsworth. "But I hadn't an idea that Paloma held any dynamite. I can't imagine how a frontier town on the alkali desert needs dynamite."

"It will probably be found that someone shipped it in a hurry,"

suggested Mr. Ellsworth.

"But how? Any fellow would be detected who had it brought in on our trains. There has been no time to I stage I it from any other point since the row with Duff started."

"It's a puzzle," admitted Mr. Ellsworth.

"It is, but it won't be for long," Reade declared confidently. "There are ways of finding out how that dynamite got into Paloma, there must be ways of finding out who caused it to be brought in."

Then, suddenly, Tom's eyes grew wider open and brighter.

"Mr. Ellsworth, I believe that dynamite was brought in before the trouble opened."

"But who would have wished to bring dynamite here until the trouble started?"

"Anyone might be interested in doing it who wanted to see trouble start."

"I'm afraid I don't follow you, Reade," observed the general manager, frowning slightly.

"There were others who wanted the job of blocking the Man-killer," Tom went on earnestly. "They wanted a lot more money for the job than we thought was necessary. I don't want to accuse anyone, but I am just a trifle suspicious that the concern of Chicago contractors--"

"The Colthwaite people!" broke in Mr. Ellsworth.

"Yes; if they were bad people, and ugly business rivals--"

"How would the Colthwaite people be able to foresee that you were going to have a fight with Jim Duff?" interposed Mr. Ellsworth.

"I'm going after the answer, if there is one. I hope to be able to tell you the answer one of these days."

Tom and Harry made two trips each, in different directions, to make sure that the watch men were awake and alert. It was nearly eleven o'clock when the general manager and his engineers turned in for a night's rest--"subject to the approval of Jim Duff," as Tom dryly stated it.

No more interruptions followed during the night, however. At daylight the watchmen sought their tents and the day force began to stir soon after.

After the steam whistle bad blown the breakfast call, Reade slipped away from his friends to inspect the laborers at the meal.

"There are some of your men absent, Mr. Mendoza," Tom murmured to the Mexican foreman.

"Yes, Senor. Some of my men slipped away in the night."

"Went off to Paloma, eh?"

Mendoza shrugged his shoulders.

"Gambling, drinking--both," nodded Tom.