McCloskey slapped his thigh.  “By George!  I’ve got a job right now!  Why on top of earth didn’t I think of him before?  He’s the man to keep tab on Hallock.”

But now Lidgerwood was frowning again.

“I don’t like that, Mac.  It’s a dirty business to be shadowing a man who has a right to suppose that you are trusting him.”

“But, good Lord!  Mr. Lidgerwood, haven’t you got enough to go on?  Hallock is the last man seen around the engine that disappears; he spends a lot of his time swapping grievances with the rebels; and he is out of town and within a few miles of here, as you know, when this wreck happens.  If all that isn’t enough to earn him a little suspicion——­”

“I know; I can’t argue the case with you, Mac, But I can’t do it.”

“You mean you won’t do it.  I respect your scruples, Mr. Lidgerwood.  But it is no longer a personal matter between you and Hallock:  the company’s interests are involved.”

Without suspecting it, the trainmaster had found the weak joint in the superintendent’s armor.  For the company’s sake the personal point of view must be ignored.

“It is such a despicable thing,” he protested, as one who yields reluctantly.  “And if, after all, Hallock is innocent——­”

“That is just the point,” insisted McCloskey.  “If he is innocent, no harm will be done, and Judson will become a witness for instead of against him.”

“Well,” said Lidgerwood; and what more he would have said about the conspiracy was cut off by the shrill whistle of a down-coming train.  “That’s Williams with the special,” he announced, when the whistle gave him leave.  “Is your flag out?”

“Sure.  It’s up around the hill, with a safe man to waggle it.”

Lidgerwood cast an anxious glance toward Dawson’s huge derrick-car, which was still blocking the main line.  The hoist tackle was swinging free, and the jack-beams and outriggers were taken in.

“Better send somebody down to tell Dawson to pull up here to your temporary siding, Mac,” he suggested; but Dawson was one of those priceless helpers who did not have to be told in detail.  He had heard the warning whistle, and already had his train in motion.

By a bit of quick shifting, the main line was cleared before Williams swung cautiously around the hill with the private car.  In obedience to Lidgerwood’s uplifted finger the brakes were applied, and the Nadia came to a full stop, with its observation platform opposite the end of the wrecking-track.

A big man, in a soft hat and loose box dust-coat, with twinkling little eyes and a curling brown beard that covered fully three-fourths of his face, stood at the hand-rail.

“Hello, Howard!” he called down to Lidgerwood.  “By George!  I’d totally forgotten that you were out here.  What are you trying to do?  Got so many cars and engines that you have to throw some of them away?”

Lidgerwood climbed up the embankment to the track, and McCloskey carefully let him do it alone.  The “Hello, Howard!” had not been thrown away upon the trainmaster.