If there was one thing more than another that Percy Rapson and Dan Medlicott coveted, it was an opportunity to accompany Sergeant Silk on one of his police expeditions on the Rattlesnake patrol. But such an opportunity came very seldom, and it was quite an exceptional circumstance that Dan happened to be able to make himself of use on the occasion when Red Derrick was captured in White Wolf Gulch.

The way it all happened was this—

Two men were riding along the trail, one on a piebald broncho, the other on a black mustang. They were on their way to the meeting place appointed by their leader, Red Derrick. Everything had been well planned, but they were not fully certain that they were safe, and they were both nervously anxious. As they came out from the gloom of a pine forest into the open, the man on the piebald broncho looked searchingly into the night darkness over his left shoulder. Then he shifted his grip on the reins and glanced uneasily at his companion.

"Say, Bill," he inquired, "you plumb sure as we ain't bein' follered?"

Bill Allison's hand went as by instinct to his revolver.

"Follered, Hen?" he questioned, looking around and listening. "Did you see anythin'?—hear anythin'?"

"Well," returned Hen, "I just notioned a while ago as I caught the clip of a horse's hoof agin a stone, way back thar. Might ha' bin a' echo. Dessay it was."

"Couldn't ha' bin anythin' else," Bill assured him. "Thar's no Injuns messin' around. Th' Mounted P'lice is busy somewhere else. Nobody knows where we are, or where we're goin'—nobody, 'cept Red Derrick hisself. No, pard, we ain't bein' follered. Guess you're right 'bout its bein' a' echo."

He jabbed his pony's flank with a spurred heel and the two broke into a quicker pace. For a couple of miles or so they continued riding side by side, along the indistinct trail, neither speaking. But within the gloom of a dark, wooded bluff they slowed down, turned abruptly from the beaten track, and pursued their way quietly, stealthily, in single file, through the long grass, descending into the hollow of a secluded coulee, where they came to a halt.

"Jim said as he'd show a light," said Bill. "Watch for it over yonder. D'ye make out the old shack?"

He pointed across the coulee to a small log hut, so overgrown with tangled creepers that in the darkness it could hardly be distinguished from the surrounding bush.

Hen Faxon nodded.

"Queer sort of a crib ter bring us to," he observed, preparing to dismount. "Makes a fellow feel some scared. Why couldn't Jim ha' done the business when he was along east yesterday?"

Bill gave a sneering little laugh.

"Pr'aps you've an idea as he'd bin wiser ter discuss the biz in the public saloon at Hickory Crossing, with a crowd of ranchers an' cowpunchers, and maybe one of the Mounted P'lice fer audience?" he suggested. "But Jim Derrick ain't that sort. He ain't no novice tenderfoot ter let any trampoosin' stranger know what cards he holds. And I reckon he holds a straight flush this game, see?"

"Um!" muttered Hen.

The two men dismounted and hobbled their ponies.

"We'll wait here till he gives a sign," said Bill, taking out his pipe.

They lay in the grass, smoking, with their eyes directed towards the dark shape of the dilapidated, deserted log cabin, which was their appointed meeting-place. After a long time of waiting, Bill Allison's broncho threw up its head and stood alert with twitching ears.

"Reckon Jim's thar now," decided Bill. "Yes, he's strikin' a light, see! Leave the ponies where they are."

He stood up and led the way across the coulee. Red Derrick met them at the ruined doorway.

"Yo're punctual, boys," he said. "Thought I heard you comin' t'other way. Everythin' all right?"

"Yep," Bill answered, following within the hut to where Derrick's lighted candle burnt in the neck of a bottle among the rank weeds that grew about the broken hearthstone.

"Sure?"

Bill nodded emphatically.

"It's all serene," he answered. "Nobody seen us start, and we ain't set eyes on a livin' human all along the trail."

"Good," said Derrick. "Y'see, I was some afraid as that all-fired, double-barrelled detective, Sergeant Silk, might ha' gotten wind of suthin'. Thar ain't a whole lot as he don't ferret out somehow. Say, he ain't been spyin' around any, has he?"

"Haven't seen him for weeks," reported Hen Faxon.

"Reckon he's gone off on another patrol," said Bill. "Anyhow, he ain't liable t' ha' gotten wind of this yer game we're startin' on, and that's sure."

"Then we're safe ter pull it off," declared Red Derrick, "and we kin lay our plans right now. But first, I suspicion you two boys is some dry, eh? Say, thar's suthin' in the shape of liquid refreshment here."

He opened his haversack and produced a bottle and a tin pannikin, and each of the three took a long drink in his turn. One of the fallen roof timbers served as a seat for Derrick and Allison. Hen Faxon seated himself on the earthen floor, with his back against one of the upright logs of the wall.

As he did so he was half-conscious of a rustling movement at the other side of the timber against which he leant. He drew himself forward an inch or two and looked round.

"Guess thar's a lynx or a fox or some sich critter sniffin' around outside," he muttered. He put his ear to a gap in the wall and listened. "Dessay it was only my fancy," he decided. "I'm some scared to-night. Allus am when thar's a risky job on hand. Give us another drink, Jim."

The sound which had disturbed him was not repeated, and his two companions paid no regard to his remark. Even if he had been correct in his surmise as to the cause of the rustling movement, there would be no possible danger in the circumstance of a fox or a lynx or any other species of wild creature sniffing around.

Nevertheless, Hen Faxon's sharp hearing had not altogether deceived him, and had his eyesight been as keen—had he put an eye instead of an ear to the open seam between the pine logs at his back—he might even in the darkness have discovered that the actual intruder was much more formidable and dangerous than was any prowling four-footed beast.

"Well, boys," began Red Derrick, pulling vigorously at his pipe. "I figure thar's no p'ticler need fer me ter say a whole lot. You've both of you got as much savee as I have how the thing's got ter be pulled off, and it's up to us ter pull it off successful. Y'see that thar stage coach is bound ter keep schedule time. Alf Bulger'll see to it. Alf's our trump card. He'll join on and take charge of the stage, as per usual, at Soldier's Knee, drivin' his team clean into our arms, so ter speak. He'll be due along the Rattlesnake section an hour before sundown. Just when it's gettin' tolerable dark, he'll enter White Wolf Gulch. That's our point, see? That's whar we're shapin' ter hold him up and collar the boodle."

"Say, thar ain't no doubt 'bout that boodle bein' on board, is there?" Hen Faxon leant forward to inquire.

Red Derrick looked at him severely across the flickering candle-light.

"Not a ghost of a doubt," he said. "Not a shadder. That's the one thing more sartin than anythin' else in the whole biz. Fifty thousand dollars' worth. That's the value, 'cordin' ter Alf, and I reckon Alf should know, him bein' stage driver and in the company's confidence. And say, boys, you've got ter see as Alf don't get scratched."

"Any passengers?" inquired Bill Allison.

Derrick shrugged his broad shoulders.

"What odds if thar is?" he retorted. "We kin deal with 'em, sure—three of us, droppin' on 'em unawares, and Alf helpin' us. Nat'rally thar'll be the messenger in charge of the boodle," he explained, "some quill-drivin', white-collared bank clerk from Ottawa. Don't figure as he need count for a lot. He ain't liable ter be anyways handy with a gun; and Tom Mason'll see as the skunk's shooter is empty. Soon as Alf enters the gulch, drivin' slow, he'll give us the signal. He'll crack his whip ter let us know as everythin's serene. Then the fun'll begin."

"We got ter fire in the air, then?" questioned Bill Allison. "We got ter do nothin' but fill the atmosphere with yells an' smoke? Seems easy!"

"The more noise we makes the better," returned Red Derrick. "But we've got ter do more'n make a clatter. Y'see, Alf Bulger c'n hardly make out as he's been held up by a gang of desperate road agents if we don't give him the evidence of a considerable pepperin' of bullet holes in the panels of his coach. As fer Mister Bank-clerk, if he shows fight—well, you kin leave him t' me. Savvy? Him and any other passengers, while you two make off with the swag."

His two confederates signified their understanding of the bold scheme by which the stage coach was to be held up and robbed: and they had now only to discuss the details of their plan of attack.

While they discussed, they proceeded to empty the bottle of what Derrick had called liquid refreshment, and it was perhaps because of his anxiety to secure his full share of the drink that Hen Faxon failed to detect a repetition of the faint rustling sound outside the hut which had previously caught his attention. It is more probable, however, that the movement was so slight that even if he had been listening for it he could not have known that it was anything more than the mere whispering of the wind in the surrounding brush.

No Indian scout, skilled in the art of taking cover, could have accomplished his purpose more silently than did the man who had stealthily crawled up to the rear of the ruined shanty to watch and listen.

Keeping still as a rock, lying at full length along the ground with an eye at a knot-hole in one of the timbers, hardly breathing lest he should betray his presence, he had heard every word that had been spoken; and now, knowing that he could discover nothing further, he was stealing away to make prompt use of his secret.

Very slowly, very silently, inch by inch, he crawled on hands and knees through the tangled brushwood and rank grass, working his way up the rising ground until he came to the edge of the coulee. Then he rose to his feet, looked back to assure himself that he had not been seen, and strode quickly but very cautiously through a belt of trees to where his horse was waiting, watching him as he approached.

"Quiet!" he whispered as he drew near, and the animal seemed to understand, for it made no movement, no slightest sound, but stood rigidly still until the rider had swung himself into the saddle.

"Steady, girlie!" he muttered. "No need to hurry, just yet."

He unbuttoned his military coat and under its cover dexterously struck a match on the milled edge of his watch. The tiny flame gleamed only for a moment upon his scarlet tunic, but in that moment he had seen the dial of his watch, with the fingers pointing to a quarter to eleven.

"Good!" he decided, as he seized the bridle rein. "We can take it easy, and yet get to Rattlesnake Ranch before sunrise."