from dawson city the yukon flows in a northwesterly direction toward the international boundary, and although the camp is scarcely more than fifty miles due east of american territory, by the river it is ninety. since the yukon is the main artery of travel, both winter and summer—there being no roads or trails—it behooved those malefactors who fled the wrath of the northwest mounted police to obtain a liberal start, for ninety miles of dead flat going is no easy run and the police teams were fleet of foot. time was when evil-doers had undertaken to escape up-river, or to lose themselves in the hills to the northward, but this was a desperate adventure at best and had issued in such uniform disaster as to discourage its practice. the police had won the reputation of never leaving a trail, and, in consequence, none but madmen longer risked anything except a dash for american soil, and even then only with a substantial margin of time in their favor.

but the winter winds are moody, the temper of the arctic is uncertain, hence luck played a large part in these enterprises. both rock and doret were sufficiently familiar with the hazards and the disappointments of travel at this time of year to feel extremely doubtful of overhauling the two mccaskeys, and so they were by no means sanguine of success as they drove headlong into the night.

both teams were loaded light; neither driver carried stove, tent, or camp duffle. sleeping-bags, a little cooked food for themselves, a bundle of dried fish for the dogs, that was the limit the pursuers had allowed themselves. given good weather, nothing more was needed. in case of a storm, a sudden blizzard, and a drop in temperature, this lack of equipment was apt to prove fatal, but neither traveler permitted himself to think about such things. burdened thus lightly, the sleds rode high and the malamutes romped along with them. when the late dawn finally came it found them far on their way.

that wind, following the snowfall of the day before, had been a happy circumstance, for in many places it had blown the trail clean, so that daylight showed it winding away into the distance like a thread laid down at random. here and there, of course, it was hidden; under the lee of bluffs or of wooded bends, for instance, it was drifted deep, completely obliterated, in fact, and in such places even a seasoned musher would have floundered aimlessly, trying to hold it. but 'poleon doret possessed a sixth sense, it appeared, and his lead dog, too, had unusual sagacity. rock, from his position in the rear, marveled at the accuracy with which the woodsman's sled followed the narrow, hard-packed ridge concealed beneath the soft, new covering. undoubtedly the fellow knew his business and the officer congratulated himself upon bringing him along.

they had been under way for five or six hours when the tardy daylight came, but even thereafter doret continued to run with his hand upon his sled. seldom did he ride, and then only for a moment or two when the going was best. for the most part he maintained a steady, swinging trot that kept pace with the pattering feet ahead of him and caused the miles rapidly to drop behind. through drifts knee-deep, through long, soft stretches he held to that unfaltering stride; occasionally he turned his head and flashed a smile or waved his hand at the man behind.

along about ten o'clock he halted his team where a dead spruce overhung the river-bank. by the time rock had pulled in behind him he had clambered up the bank, ax in hand, and was making the chips fly. he sent the dry top crashing down, then explained:

"dem dogs go better for l'il rest. we boil de kettle, eh?"

rock wiped the sweat from his face. "you're certainly hitting it off, old man. we've made good time, but i haven't seen any tracks. have you?"

"we see 'em bimeby."

"kind of a joke if they hadn't come, after all—if they'd really gone out to hunker. gee! the laugh would be on us."

"dey come dis way," 'poleon stoutly maintained.

soon a blaze was going; then, while the ice in the blackened tea-bucket was melting, the drivers sliced a slab of bacon into small cubes and fed it sparingly to their animals, after which they carefully examined the dogs' feet and cleaned them of ice and snow pellets.

the tea was gulped, the hardtack swallowed, and the travelers were under way again almost before their sweaty bodies had begun to chill. on they hurried, mile after mile, sweeping past bends, eagerly, hopefully scanning every empty tangent that opened up ahead of them. they made fast time indeed, but the immensity of the desolation through which they passed, the tremendous scale upon which this country had been molded, made their progress seem slower than an ant-crawl.

eventually 'poleon shouted something and pointed to the trail underfoot. rock fancied he could detect the faint, fresh markings of sled runners, but into them he could not read much significance. it was an encouragement, to be sure, but, nevertheless, he still had doubts, and those doubts were not dispelled until doret again halted his team, this time beside the cold embers of a fire. fresh chips were scattered under the bank, charred fagots had embedded themselves in the ice and were frozen fast, but 'poleon interpreted the various signs without difficulty.

"here dey mak' breakfas'—'bout daylight," said he. "dey go slower as us."

"but they're going pretty fast, for all that. we'll never get them this side of forty mile."

"you don' spec' it, do you? dey got beeg scare, dem feller. dey runnin' so fas' dey can."

forty mile, so called because the river of that name enters the yukon forty miles above the boundary, was a considerable camp prior to the dawson boom, but thereafter it had languished, and this winter it was all but deserted. so, too, was cudahy, the rival trading-post a half-mile below. it was on the bars of this stream that the earliest pioneers had first found gold. here at its mouth, during the famine days before the steamboats came, they had cached their supplies; here they had brewed their hootch in the fall and held high carnival to celebrate their good luck or to drown their ill-fortune.

rock and his companion pulled up the bank and in among the windowless cabins during the afternoon; they had halted their dogs before the mounted police station, only to find the building locked and cold. the few faithful forty-milers who came out to exchange greetings explained that both occupants of the barracks had gone down-river to succor some sick indians.

rock was disgusted, but his next question elicited information that cheered him. yes, a pair of strangers had just passed through, one of them an active, heavy-set fellow, the other a tall, dark, sinister man with black eyes and a stormy demeanor. they had come fast and they had tarried only long enough to feed their dogs and to make some inquiries. upon learning that the local police were on the main river somewhere below, they had held a consultation and then had headed up the forty mile.

"up forty mile?" rock cried, in surprise. "are you sure?"

"we seen 'em go," his informant declared. "that's what made us think there was something wrong. that's why we been on the lookout for you. we figgered they was on the dodge and hard pressed, but we couldn't do nothing about it. you see, it's only about twenty-three miles to the line up forty mile. down the yukon it's forty. they been gone 'most two hours, now."

"what do you want 'em for?" another bystander inquired.

"murder," rock exclaimed, shortly; then he heaved his sled into motion once more, for 'poleon had started his team and was making off through the town. down into the bed of the smaller stream the pursuers made their way and up this they turned. again they urged their dogs into a run. it took some effort to maintain a galloping pace now, for the teams were tiring, and after some mental calculations rock shook his head doubtfully. of course, his quarry was at a disadvantage, there being two men to one sled, but—twenty-three miles, with a two-hour start! it was altogether too great a handicap. the lieutenant had figured on that last forty miles, the last five or ten, in fact, but this change of direction had upset all his plans and his estimates. evidently the mccaskeys cared not how nor where they crossed the line, so long as they crossed it quickly and got canadian territory behind them. barring accident, therefore, which was extremely unlikely, rock told himself regretfully that they were as good as gone. two hours! it was too much. on the other hand, he and 'poleon now had a fresh trail to follow, while the fleeing brothers had unbroken snow ahead of them, and that meant that they must take turns ahead of their dogs. then, too, fifty miles over drifted trails at this season of the year was a heavy day's work, and the mccaskeys must be very tired by now, for neither was in the best of condition. in the spring, when the snows were wet and sled runners ran as if upon grease, such a journey would have been no great effort, but in this temperature the steel shoes creaked and a man's muscles did not work freely. men had been known to play out unexpectedly. after all, there was a possibility of pulling them down, and as long as there was that possibility the mounted policeman refused to quit.

rock assured himself that this flight had established one thing, at least, and that was pierce phillips' innocence of the courteau killing. the murderers were here; there could be no doubt of it. their frantic haste confessed their guilt. friendship for the boy, pride in his own reputation, the memory of that ovation he had received upon leaving, gave the officer new strength and determination, so he shut his teeth and spurred his rebellious limbs into swifter action. there was no longer any opportunity of riding the sled, even where the trail was hard, for some of the police dogs were limping and loafing in their collars. this was indeed a race, a marathon, a twenty-three-mile test of courage and endurance, and victory would go to him who could call into fullest response his last uttermost ounce of reserve power.

doret had promised that he would show his trail-mate how to travel, and that promise he had made good; all day he had held the lead, and without assistance from the lash. even now his dogs, while not fresh, were far from exhausted. as for the man himself, rock began to feel a conviction that the fellow could go on at this rate eternally.

luck finally seemed to break in favor of the pursuers; accident appeared to work in their behalf. the day was done, night was again upon them, when doret sent back a cry of warning, and, leaping upon his sled, turned his leader at right angles toward the bank.

his companion understood the meaning of that move, but the police team was less responsive to command, and before rock could swing them he felt his feet sink into soft slush.

"dam' overflow!" doret panted when the two teams were safely out upon the bank. "you wet your feet, eh?"

apprehensively the officer felt of his moccasins; they were wet to the touch, but as yet no moisture had penetrated his socks. "you yelled in the nick of time," he declared, as he dried his soles in the loose snow.

"dem feller got in it ankle-deep. i bet we fin' camp-fire soon."

this prediction came true. as the travelers rounded the next bluff they smelled the odor of burning spruce and came upon a trampled bed of boughs beside which some embers were still smoldering.

"jove! that gives us a chance, doesn't it?" rock panted.

his companion smiled. "we goin' start travel now, for sure. dey can't be more 'n a mile or two ahead."

down upon the river-bed the teams rushed. with biting lash and sharp commands the drivers urged them into a swifter run. rock was forcing his dogs now; he made the smoke fly from their hides when they lagged. he vowed that he would not permit this french canadian to outdistance him. he swore a good deal at his malamutes; he cursed himself as a weakling, a quitter; anger at his fatigue ran through him.

the travelers were up among the hills by now. occasionally they passed a deserted cabin, home of some early gold-digger. valleys dark with night opened up to right and to left as the forty mile wound higher, deeper into the maze of rounded domes: the boundary was close at hand. the hillsides hid their feet in black thickets of spruce, but their slopes were thinly timbered, their crests were nearly bare, and the white snow gave off a dim radiance that made traveling possible even after the twilight had deepened. by and by it grew lighter and the north horizon took on a rosy flush that spread into a tremendous flare. the night was still, clear, crackly; it was surcharged with some static force, and so calm was the air, so deathlike the hush, that the empty valley rang like a bell. that mysterious illumination in the north grew more and more impressive; great ribbons, long pathways of quivering light, unrolled themselves and streamed across the sky; they flamed and flickered, they writhed and melted, disappearing, reappearing, rising, falling. it was as if the lid had been lifted from some stupendous caldron and the heavens reflected the radiance from its white-hot contents. mighty fingers, like the beams of polar search-lights, groped through the voids overhead; tumbling waves of color rushed up and dashed themselves away into space; the whole arch of the night was lit as from a world in flames. red, yellow, orange, violet, ultra-violet—the tints merged with one another bewilderingly and the snows threw back their flicker until coarse print would have been readable. against that war of clashing colors the mountain-crests stood out in silhouette and the fringe of lonely wind-twisted trunks high up on their saddles were etched in blackest ink.

it was a weird, an unearthly effect; it was exciting, too. as always when the aurora is in full play, the onlookers marveled that such a tremendous exhibition of energy could continue in such silence. that was the oddest, the most impressive feature of all, for the crash of avalanches, the rumble of thunder, the diapason of a hundred niagaras, should have accompanied such appalling phenomena. it seemed odd indeed that the whine of sled runners, the scuff of moccasins, the panting of dogs, should be the only audible sounds.

there were other overflows underfoot now, but the cold had frozen them and the going was getting constantly better. the snow was thin and in places the sleds slewed sidewise and the dogs ran on slack traces across long stretches of bare glare ice. it was while negotiating such a place as this that rock paid the price of his earlier carelessness. doret's dry moose-skin soles had a sure grip, hence he never hesitated, but the lieutenant's moccasins were like a pair of tin shoes now and, without warning, he lost his footing. he was running swiftly at the moment; he strove to save himself, to twist in midair, but he failed. 'poleon heard a cry of pain and dismay, so he halted his team and came striding back. rock raised himself, then took a step, but faltered and clung helplessly to the handlebars. he began to curse furiously; he undertook to estimate the extent of his injury, then explained:

"my foot doubled under me and i came down on it like a ton of bricks.

by heavens! i believe something broke!"

'poleon was solicitous. he blamed himself, too. "it's dem wet moccasin'. i should have stop' an' mak' you change," said he.

"we can't stop," rock groaned. "i'll be all right as soon as—" the words ended in another explosive oath as he again put his weight upon the injured member. blasphemy poured from his lips as repeatedly he tried to force his foot to carry him. he cursed himself for a clumsy, blundering ass; he shouted at his dogs; he sent his sled forward and lurched along behind it, half supporting himself, until 'poleon finally halted him.

"it's no good mak' bad t'ing worse, m'sieu'," the woodsman declared. "you bus' him for sure, an' it's no use goin' furder. s'pose mebbe we boil de kettle, eh?"

"and let them get away clean? when we had 'em? they can't be a mile ahead. let 'em slip between our fingers?" raved the officer. "i can't. i won't—"

"we mak' li'l fire an' look him over dat foot. me, i t'ink you don' walk no more for two, free week'."

"you go! i'll deputize you! get 'em, doret, quick! you can do it! i'll wait! go ahead!"

the other nodded. "sure, i can get 'em! i never have no doubt 'bout dat in de least, but it's better we fix you comfor'ble."

"they'll be across, i tell you—over the line—"

"i came pas' dat place more 'n once or twice"—the french canadian grinned—"an' i never seen it no line." he forced his companion to lower himself upon the sled, then swung it toward the river-bank, calling upon his own lead dog to follow. up and into the shelter of the spruce he drove the police team; quickly he felled dry wood and kindled a fire. this took but a few moments, but rock was wet with sweat and in consequence he was shivering wretchedly; his teeth were chattering even before the blaze had taken hold. 'poleon continued to work with what speed he could, and in a surprisingly short time he had built a snug wickiup and filled it with boughs. this done, he unhitched and fed both teams, spread rock's sleeping-bag under the shelter, and set a pail of snow to melt. by the light of the fire he examined the latter's injury, but could make little of it, for already it was badly swollen and every manipulation caused its owner extreme pain. there were no remedies available; there was not even a vessel of sufficient size in which to bathe the foot; hence 'poleon contented himself by bandaging it and helping his trail-mate into bed.

not since leaving dawson had either man tasted hot food, but their hunger was as nothing to their thirst. even in this length of time their bodies had shrunk, withered, inside their clothing, and for perhaps an hour they took turns greedily draining the pail of its tepid contents. under intense cold the human body consumes itself at a rapid rate. once it has burned itself out it preys upon those deep-hidden forces which nature holds in reserve, and the process of recuperation waits upon a restoration of a normal balance of moisture.

both men were weighed down by an aching, nightmare fatigue, and as they sat gulping hot water, absorbing heat from within and without, their muscles set and they felt as if their limbs had turned to stone.

but, once the first mad craving for drink had been assuaged, they fried bacon and made tea. like wolves they fell upon the salt meat; they dipped the hot grease up in their spoons and swallowed it with relish; they crunched their hardtack and washed the powdery mouthfuls down with copious draughts from the blackened pail. when the tea was gone they brewed another scalding bucketful.

rock lay back, finally, but the movement caused him to bare his teeth in agony. at 'poleon's quick inquiry he shook his head.

"i'm all right," he declared. "good for the night. you can pull out any time you want to."

"dere's plenty tam." 'poleon lit his pipe and reached again for the tea-bucket.

"better go before you stiffen up."

"i go bimeby—sooner i get li'l drinkin' done."

"they'll fight," rock announced, after a silence of perhaps five minutes. "i feel pretty rotten, playing out like this."

"you done firs' rate," the woodsman told him. "if i come alone i catch 'em ten mile below, but—li'l tam, more less, don' mak' no differ."

"i believe you would have got 'em," the officer acknowledged. after a time he persisted: "they'll put up a battle, doret. you'll need to be careful."

'poleon was squatted indian fashion over the blaze; he was staring fixedly into the flames, and an aboriginal reticence had settled upon him. after a long time he answered: "mebbe so i keel de beeg feller. i dunno. so long one is lef' i mak' him clear dat boy phillips."

"decent of you to take a chance like that for pierce," rock resumed. "it's different with me; i have to do it. just the same, i wouldn't care to follow those fellows over the boundary. i don't think you'd better try it."

in spite of his suffering, the lieutenant fell into a doze; whether he slept ten minutes or an hour he never knew, but he awoke, groaning, to find the big woodsman still bulked over the campfire, still smoking, still sipping tea. rock ate and drank some more; again he slept. for a second time his pain roused him, and once more he marveled to discover 'poleon occupied as before. it seemed to him that the fellow would never satisfy himself. eventually, however, the latter arose and made preparations to leave.

the northern lights had flickered out now; the empty sky was sprinkled with a million stars which glittered like scintillating frost jewels frozen into the dome of heaven; there were no sounds whatever to break the deathlike silence of the night, for the arctic wastes are all but lifeless. there were no bird-calls, no sounds of insects, not even the whisper of running water, for the river was locked deep beneath its icy armor.

"you got 'nough wood to las' long tam," 'poleon declared. "if i don' come back, dem forty mile police is sure to pick you up."

"i can go in alone if i have to," the injured man declared. "au revoir and good luck."

'poleon made no attempt to hurry his tired team; for several miles he plodded along behind them, guiding them to right or left by a low-spoken word. years before, he had rocked on the bars of this stream; therefore its landmarks were familiar to him, and in spite of the darkness he readily identified them. in time he made out the monuments marking the international boundary, and a short distance beyond that point he unhitched his dogs, then took a carbine from his sled and slipped it full of shells. next he removed his lash rope, coiled it, and placed it in his pocket, after which he resumed his journey alone.

occasionally he dimly glimpsed deserted cabins, habitations built by the gold-diggers of other days. carefully he followed the all but indistinguishable sled tracks ahead of him until they swerved abruptly in toward the bank. here he paused, pulled a mitten, and, moistening a finger, held it up to test the wind. what movement there was to the air seemed to satisfy him, for, step by step, he mounted the steep slope until his head finally rose over its crest. against the skyline he now made out a small clearing; straining his eyes, he could see the black square of a cabin wall. no light shone from it, therefore he argued that his men had supped and were asleep. he had assumed that they would not, could not, go far beyond the boundary; he had purposely allowed them sufficient time in which to overcome the first agony of fatigue and to fall asleep. he wondered apprehensively where they had put their dogs, and if by any evil chance the mccaskey team included an "outside" dog of the watchful, barking variety.

gingerly he stepped out, and found that the snow underfoot gave off only the faintest whisper. like a shadow he stole closer to the hut, keeping the imperceptible night breeze in his face.

so noiseless was his approach that the tired dogs, snugly curled each in its own deep bed of snow, did not hear him—your malamutes that are broken to harness are bad watch-dogs at best. not until he had melted into the gloom beneath the wide overhang above the cabin door did the first disturbance come. then something started into life and the silence was broken.

'poleon saw that a canvas sled-cover had been used to curtain the door opening, and during the instant following the alarm he brushed the tarpaulin aside and stepped into the pitch-black interior.

it had been a swift maneuver, the result of a lightning-like decision, and not so reckless as it appeared.

he stood now with his back to the rough log wall, every muscle in his body taut, his ears strained for some sound, some challenge. he had been prepared for a shot out of the darkness, but nothing came. his lungs were filling with the first deep breath of relief when a sleepy voice spoke:

"that you, frank?" 'poleon remained fixed in his tracks. "frank!" there was a moment's pause, then, "frank!"

followed a rustle as of a body turning, then a startled mumble in answer.

"was that you?" joe mccaskey's voice again demanded.

"me? what—?"

"was you outside?"

"outside?"

"i heard the dogs rowing. they're stirring now. hear 'em? i'll swear i saw that fly drop—" mccaskey's words died out and again the interior of the cabin became soundless.

"who's there?" the former speaker suddenly barked.

when another moment had dragged by, a sulphur match was struck. for a second or two it shed a sickly blue radiance sufficient only to silhouette a pair of hands cupped over it; then, as the flame ignited the tiny shaft, it burst into a yellow glow and sent the shadows of the cabin leaping.

joe mccaskey uttered a cry, a scream. the flame was crushed in his palms and again the cabin was ink black. it remained as silent as before except for a dry rattling of breath in the elder brother's throat.

"wha—what'd you—see?" the younger one gasped. both men were now fully awake, but, disregarding the question, joe cried, wildly:

"who are you? what d'you want?" and then, when no answer came: "christ!

say something."

'poleon could hear the wretch moisten his dry lips; he could picture both men sitting bolt upright in their sleeping-bags; he could feel the terror that was creeping over them.

"who'd you see?" frank whispered again.

"s-something big! right there! by god! something's in here!"

joe's tone was firmer now; nevertheless, fright still held him motionless, paralyzed. he was staring with blind eyes into the velvet blackness, and his flesh was rippling with a superstitious horror of that formless creature he had glimpsed. what was it that had walked in out of the night and now crouched ready to spring? nothing human, nothing natural, that was sure.

similar thoughts raced madly through his brother's brain, and the latter let forth a thin wail—almost a sob. the sound set joe into motion. swiftly but clumsily he fumbled through the dry grass with which his bunk was filled. he uttered a throaty curse, for he had laid his revolver by his side, right where his hand would fall upon it. where was the thing—?

joe's body turned rigid, his shaking fingers grew stiff and useless, when out of the darkness came a sigh—faint but unmistakable; whence it issued neither brother could tell.

with another shriek frank fell back and burrowed into his sleeping-bag.