The millionaire was seated close to the open window of the luxurious Pullman car that waited in Macleod Station. He was looking across the platform at a tall man in a red tunic.

"Fine, handsome chaps, these North-West Mounted Police," he remarked to his fellow-passenger. "Look, Colonel, look at that one on the platform! Quite a picture of soldierly bearing; fit to be an officer in the Guards so far as outward appearance goes! Just a trifle too tidy, perhaps; too consciously elegant; too much as if he were intended as an ornament rather than for serious active service. There's not a crease or a flaw in his scarlet tunic, see! Hat set on at the right angle, not a strap out of place or a button that doesn't shine enough to dazzle your eyes. Even the way he carries his overcoat and holds his carbine in the crook of his arm makes one think he'd studied the effect in front of a looking-glass. Indeed, the only departure from military precision that I can detect is his wearing his chin-strap at the back of his head instead of in the regulation manner."

There was no response to these criticisms, and the millionaire went on after taking one or two puffs at his very large cigar—

"Do you suppose, now, Colonel, that he could do any serious business with that service revolver of his? You'd think by the cartridges in his bandolier that it was intended for use. And do you suppose that a dandy such as he is could do any real good in a scrimmage?"

The passenger on the other side of the dining-table sipped at his cup of black coffee.

"I don't only suppose, Sir George," he answered slowly, glancing out through the open window. "I happen to know. The man you're looking at isn't always dressed as if he had just come out of a bandbox to parade his elegance and his good figure on a railroad platform. I have seen him looking very different, riding out on the lone patrol. If he is clean and tidy now, it is because he hates slovenliness of any kind, and, perhaps, too, because he likes to hide the fact that the one purpose of his existence is to do his duty with efficiency. You ask if he could do any serious business with his revolver. My dear Sir George, that chap is considered the best shot in all Canada. He is that, just as surely as he is the best all-round scout, the best rider, and the bravest man in the Dominion. I could tell you a lot about him, but I see by the twinkle in his eye that he knows we are talking of him, and he hates to be noticed. Ah, he's coming this way."

Sir George produced his box of cigars as the soldier policeman strode across the platform towards the waiting cars. The Colonel rose from his seat and leant his elbows on the frame of the window.

"How d'you do, Sergeant Silk?" he said in greeting, extending his hand. "Say, it seems queer to see you on foot and not in the saddle. You're off duty, I suppose?"

"No, Colonel," returned Silk, "not exactly. My broncho is in the horse box at the rear. I'm going on by this train."

"Have a cigar, Sergeant," urged Sir George.

Silk took one, biting off the end with his sharp, even teeth, as cleanly as if he had cut it with a knife.

"Won't you come in along with us?" the millionaire invited.

Silk shook his head.

"No, thank you, sir. I go third-class, and I may have to jump off between stations." He glanced at the Colonel. "I'm going west to see if I can find out something of the affair that happened along the line last night," he explained. "Perhaps you heard of it? No? Well, you see, the 7.42 was held up by a gang of train robbers, who managed to board her while she was side-tracked, waiting for the limited express to pass. The engine-driver was killed in the scuffle, and the conductor was badly hurt. I'm going as far as Hill Crest to have a word with the conductor, if he is well enough to be examined."

"It is to be hoped there's no danger of those train thieves paying us a visit to-night," said the millionaire anxiously. "I should hardly have expected to meet such gentry in Canada."

Sergeant Silk shook his head and smiled as he struck a match to light his cigar.

"They were caught, sir," he said, enjoying the aroma. "We happened—my broncho and I—to drop on them as they were escaping with the swag; and they are here in Macleod, safe under lock and key."

"What?" exclaimed the millionaire. "A gang of armed desperadoes, you say, caught—arrested—by you and your horse alone?"

Silk dropped the extinguished match and carefully trod it under foot. Experienced prairie rider as he was, he was always cautious about fire.

"You've got to allow something for my being in uniform," he smiled. "Law-breakers out here have a wholesome dread of the Mounted Police."

Touching the wide brim of his hat with a forefinger, he turned away, striding along the platform with a military clink of spurs.

He went towards the front of the waiting train, where the engine had just been coupled and was being oiled up for the run along the branch line from Macleod to Crow's Nest Pass. The district superintendent stood by and was reprimanding the engine-driver, who had evidently been making some complaint about his job.

"What's the matter with you that you register for rest?" the superintendent wanted to know. "You know we're short handed, Ted Chennell bein' killed. You've got ter take Ted's place. You've only been at work twenty hours. There's Tom Morden has been on his engine twenty-eight hours, and Tom ain't askin' for rest yet. Say, some of you fellows ought to get a job clerkin' in a drug store. This yer train's got to go. You're the only available man to take her, and that's straight."

Sergeant Silk puffed for a few moments at his cigar before speaking.

"Seems to me, Mr. Garside," he remarked casually, "that Halkett and his engine are about on a par. They're both promising candidates for hospital."

The superintendent looked round at him in surprise, resenting his interference.

"What's the matter with the engine?" he snapped. "Ain't she good enough? What's wrong with her? I allow you knows a lot about hosses, Sergeant. Thar's not many men in the Prairie Provinces knows as much. But come to locomotive engines, all that you know wouldn't take up much room on a news-sheet. I reckon I can give you points and get in front of you every time. What's the matter with 99, anyhow? You ain't overhauled her."

Sergeant Silk shifted his carbine to his other arm.

"I happen to have had a look at her this morning when she was lying in the siding," he responded lightly, regarding number 99 as if she were a horse, "and with all deference to your greater experience, Mr. Garside, I'd say that, like Halkett, she is suffering from overwork. She wants rest. She's needing a tonic. She ought to be put out to grass. Her truck centre castings are weak; her driving wheel tyres have grooves in them half-an-inch deep; the coupling pin of the tender is worn loose; she wants a new throttle latch-spring, and some of her tubes are leaky. She's wheezing now as if she had congestion of the lungs. Dare say she'd do credit drawing freight wagons; but for passenger cars—well, it's your business, not mine."

Mr. Garside stood with his feet apart and his hands on his hips, critically watching Sergeant Silk through the narrowed slits of his watery eyes.

"If you know such an almighty lot about locomotives, Sergeant," he said, "and if you calculate as Joe Halkett ain't fit and capable to manage his own business, pr'aps you'll condescend to take the train along yourself. She's scheduled to start in three minutes from now, and there's no time to change either engine or driver, see?"

Sergeant Silk looked at the superintendent sharply.

"Are you serious?" he questioned. "Do you really mean it?"

"Sure!" nodded the superintendent. "I allow there's some truth in what you say. She ain't just in the best of health, and there's room in the cab if you'll take charge. You can at least keep an eye on that throttle latch-spring, and keep Joe from droppin' asleep so as he don't run past the switches when the limited is comin' along behind."

Silk glanced upward into the cab, where Joe Halkett stood awaiting the signal to start.

Joe was looking exceedingly green and ill. He was a tallish fellow, wiry and muscular, with a hard face, dark hair, and sharp, peery eyes. He was reputed to be one of the best drivers in the Canadian Pacific Railway service; it was said that he could manage a cranky engine better than any other engineer west of Winnipeg. But Silk had already noticed that there was something queer about his manner this evening. There was a curious light in his peery eyes and a curious look on his face that did not inspire confidence.

In spite of the roar made by the steam escaping from the safety valve, Joe had heard the superintendent's suggestion that the soldier policeman should ride in the cab, and he signed beckoningly with a backward toss of his head while Silk hesitated.

"You may as well come along, Sergeant," he pleaded. "I tell you straight, I ain't fit fer duty to-night, and I'd sooner take on any other trip than this one to Crow's Nest. It ain't my reg'lar line, and I'm some scared. I'm all of a tremble. I'd oughter be home in bed. Ask Dick if I oughtn't."

Dick, his fireman, paused in his work of shovelling coal into the fire-box.

"This yer train ain't anyways safe, Joe drivin'," he said, as the superintendent turned on his heel and strode back towards the rear of the train. "Dunno what's come over him."

Sergeant Silk needed no urging. He caught at the rail, mounted the footplate, and swung himself into the cab.