A faint sound from above echoed throughout the alleyway, and Stirling turned his head, listening with every sense alert. The sound was repeated, then footfalls grated on the deck planks. The clank of the engines and the whirling shaft drowned out further steps in the cabin.

Stirling reached toward the thrust bearings, measured the distance, and thought deeply. He was directly beneath the alleyway which extended from the staterooms to the after companion—the girl and Slim, the Frisco dock rat, were above him.

He touched the planks, feeling the seams between the inch-thick decking. He traced these seams and found that they ended in a coaming at each side of the shaft alley. These were secured to the deck beams by screws which in turn were covered by tree-nails. The barrier seemed impassable.

The throbbing of the screw, driven to its limit, had a lulling effect upon Stirling, who sank to his knees and crawled along the alleyway until his fingers touched a thrust block; sitting on this he dropped his head into his greasy hands and thought, his brain swirling in the maze of doubt and unreality.

He had no tool with which he could cut his way upward, and his problem was to get in communication with the girl so that a passage could be bored through the deck planks.

The polished shaft at his side attracted his attention and he felt of it, counting the revolutions. They were slightly faster than the beat of his pulse. The power of a thousand horses was there in that rod of steel, and he wondered vaguely if there was any way to turn it to account.

The covers for the thrust blocks and shaft bearings were firmly bolted down. He groped about and searched every corner of the alleyway, finding an inch bolt and a battered oil can. These he placed by the thrust block and continued the search.

A faint light from the engine room illuminated the forward end of the shaft alley, and he crawled to this opening and peered through. The low-pressure cylinder and the engine frame prevented further scrutiny, but the shadows that moved across the gratings above the cylinder marked the presence of the revolutionists. One, perhaps, was on guard.

Stirling thrust his fingers through the plate which had been nailed to prevent his escape. Straining, he saw that he could move the lower section of iron sheeting. An object under the after bearing of the engine had attracted his attention—a long strip of leather belting coated with grease and oil.

He moved the plate, and waited; then he crawled halfway through the opening and secured the belt, Backing carefully, he worked his way aft to the thrust block.

He now had a belt and a bolt and with these crude tools he intended boring through the planks over his head. The task was a painful one. He would have to arrange the belt so that it would run under the shaft and over the bolt, which was turned by the shaft's power. Its corners might work through the plank.

He found that the bolt was too small in diameter to secure any result, and that the belt slipped and would not turn the shank. He laid the bolt down and picked up the oil can, whose shape suggested the solution of the problem.

Removing the oil spout by unscrewing it from the top of the can, he inserted the bolt in its place. The can turned freely with the bolt as an axle.

Stirling smiled through the grime upon his features. His mind had evolved a saw of the superior order, power driven and bound to be effective. He waited before he went on with the experiment.

The seething of the water told him that they were still hurtling through the lane of ice, and floes grated alongside. A shout echoed backward from the engine room, and the clank of steam-driven rods rose to a crescendo of effort. The Pole Star was striking out to open sea and the unknown waters to the north and east of Point Barrow.

The cutter cruiser had been distanced, and the Bear was a slow third in the chase. There was no way to tell where the pursuit would lead. Stirling thought dimly of the northeast passage and the way to Baffin Bay. Only madmen could effect such an enterprise.

Steps sounded above as Stirling toyed with the can, and he heard them going aft. Others followed; these were lighter. There came then the faint echo of a scuffle and the low cry of a woman, followed by a man's rude laugh as the light steps ran forward and a door slammed.

Stirling constructed the scene in his mind: The dock rat had seized the girl and embraced her, and she had torn herself from his grasp. The slamming door told that she had barricaded herself in the cabin. It was time to interfere. The inch-thick planks overhead formed the only obstruction, and he felt of them, then reached for the oil can.

The belt tightened over the polished shaft and over the rim of the can, which was at least three inches in diameter. The bolt acted as a rod, and the cutting edge as it touched the plank ground through for a quarter inch and then refused to work deeper.

Stirling saw the reason for this: The copper of the can had no abrasive edge. He lowered the can, drew out his revolver, and started nicking the metal. Each blow sounded like a hammer stroke in his straining ears, and he feared to dent the bottom of the can so freely that it could not be straightened. He pocketed the revolver and felt the edge. It was rough, at any rate.

The improvised saw now cut into the overhead plank as he pressed the bolt upward with straining arms. The belt slipped at times, but he waited and tried anew. The power which was in the tail shaft of the engines was sufficient for a thousand saws.

Dust and splinters dropped down upon his tense face, but he held on grimly with one determination mastering his thoughts: The girl was in danger. She was barricaded in her stateroom, and the dock rat was probably sitting by the great table in the main cabin—with a vast reservoir of gin and whisky from which to draw.

Stirling felt the edge of the can bite through the plank in one place. He lowered it and examined the opening. The belt had stretched under the strain and had permitted a cut of seven or eight inches in length.

Crossing the belt, Stirling started a second cut at a right angle to the first, and worked on with his arms aching and growing numb from the strained position. The oil in the can had served for lubrication to the bolt, but when this oil dried, the bolt squeaked, and the can became hot.

He lowered it from the cut in the deck plank and the smell of hot oil in the shaft bearings gave him an idea. There was enough grease and oil packed with waste there to keep the bearings cool. He lifted a cover and dug out a handful of dripping packing, which he squeezed into the can. The bolt was now lubricated.

Though working in almost total darkness, he made rapid progress, and still no sound came from above. The dock rat probably was sleeping across the table; the girl had not moved in her cabin.

The first faint light which streamed through the crack he made steeled Stirling to renewed efforts. He enlarged the opening and stood erect.

The view was a limited one of an ornate ceiling stamped here and there with fresco and border designs. In the centre of this ceiling gleamed the frosty light from an electric dome. Three lamps burned, despite the fact that a soft glow was filling the splendid cabin. This glow came from the breaking dawn which made rosy the deck light and cabin companion.

Stirling removed his eye from the crack and felt the grooves he had cut in the planking. They were almost sufficient for his purpose. He trimmed a corner with his improvised saw, ran the saw through a deep cut till it severed the plank's edge, then pressed firmly upward. The trapdoor he had cut was held by only a few splinters.

He waited and reviewed his position. The revolutionists were busy with the engines and the furnaces, and their shouts came aft with muffled curses. The clang of a bell told that the leader had urged more steam, and the ship was hurtling through a sea free from ice. Stirling could hear no grating along the run.

He worked forward, guiding himself by the touch of the polished tail shaft. The barricade of iron plates was an effective barrier to a sudden rush. There was scant danger from the Russians. The sentry they had placed on guard stood high on the gratings overlooking the opening to the shaft alley. Stirling peered through a crack in the plates and watched him. He was looking intently at the two intermediate cylinders.

Working aft with careful steps, Stirling reached his trapdoor and listened. A sound of deep breathing came to him. Slim, the dock rat, was directly above, where he choked now and then, and his arms moved over the racks of the table. Then he was still—save for the drunken breathing which subsided almost to nothingness.

Stirling braced his shoulders against the planks, pressed his feet upon the shaft bearing, and strained with every muscle. A splintering noise sounded. A second thrust tore loose the last of the planks. They showered about him as he reached upward, rested his elbows on the edge, and sprang to the deck of the cabin.

Slim raised an arm, fell forward, lifted his chin, and turned it in a slow arc. His eyes blinked as Stirling lunged for him with a bearlike glide which was not to be denied. Strong fingers clasped about the dock rat's throat; he was lifted from his chair and hurled across the floor of the cabin. Stirling was after him with a quick stride.

The struggle which followed was terrible in its intensity. Stirling had the strength given to outdoor men; he was unskilled, however, and faint from loss of sleep and food. Slim had learned boxing and wrestling along the San Francisco water front. He squirmed to his knees, twisted from Stirling's grip, and lowered his head for a rush. Stirling met this attack with a savage reaching of arms and a grunt as Slim uppercut with vicious strength. They fell into a clinch, they swayed and staggered about the cabin, overturning chairs and stools.

Stirling's clean living began to tell as the Ice Pilot recovered his wits and became more careful. Lunging blows straightened and became jabs, hugs gave place to standing exchange of blows. The dock rat leered from puffed eyes and searched about for a weapon. A brass bomb gun and a Remington rifle lay across the table. He dodged and reached for the bomb gun, his fingers closing over the barrel, when Stirling leaped the distance and wound his arms about Slim's waist.

The dock rat, catapulted through the air, crashed against the sheathing of the starboard wall. He managed to rise, but Stirling was over the planks and upon him with a vicious outthrust of his jaw. The madness of the struggle had completely mastered the Ice Pilot, who fought furiously.

Soon Slim lay still. Stirling, looking about for a cord or line, saw a tassel protruding from a curtain which covered the alleyway leading aft. Jerking this loose, he lunged swiftly to Slim's side, drew his arms behind him, and completed a sailor's job of tying and splicing from which no man could escape.

The dock rat opened one eye and moaned. Stirling drew back and glanced sternly at him, his bulk seeming to fill the cabin.

Slim closed his eyes and moaned for a second time. "Let me loose," he managed to say.

"Stay there!" Stirling said with a slow glance around.

The curtain attracted his attention. It had been partly wrenched from its pole by the drawing away of the cord. Beyond it lay the alleyway and the cabins of the after part of the ship. The girl's cabin was one of four.

"Which stateroom is the girl in?" he asked, leaning over Slim.

The sailor squirmed and dragged at his arms where they were bound, rolled over, and stared upward at the deck. A light streamed down from the barricaded companion, a light which heralded the rising of the sun. Stirling followed the dock rat's glance and studied the shadow, then wheeled swiftly and saw a tiny ship's clock set in the wall. A hasty calculation of time and shadow showed him that the Pole Star was driving east by true reckoning and north by compass. The variation was all of ninety degrees.

He listened to the progress of the ship as he waited for the dock rat to answer his question. The throbbing of the screw and the swift rush of water under the counter showed that the revolutionists were still extending their efforts. The great bight of sea beyond Point Barrow and off the mouth of the Mackenzie River was being crossed. The land ahead would be unknown territory, filled with danger and starvation.

Weakly Stirling turned; all the fight seemed to have left him, and he swayed as he glanced downward. The sailor had closed his lips in a hard line, and there was malice and calculation in his sharp, darting glances about the cabin.

Stirling shrugged his shoulders, dropped on one knee, and felt the cord. It was drawn sufficiently tight. Rising slowly, the Ice Pilot breathed deeply, feeling the aching muscles of his chest as they expanded; then he set in order the chairs and stools of the cabin and lifted the rifle until it swung in a natural manner under his right armpit.

"Stay right there!" he commanded as he glanced toward the sailor. He was surprised at the sound of his own voice, unnatural and falsely tuned.

Shaking his head with weariness, he advanced to the curtain, brushed it aside with his left hand, and strode down the alleyway, where four doors offered themselves. Each was closed. He knocked at the first, but there was no answer; it was the same with the second.

The third door proved to be that of the girl's room. He heard her stirring inside as he repeated the knock, then listened with bent head. He felt the room was sacred—he had known so little of women that they all were holy to him, and he told himself that he was committing a sacrilege.

He tapped again—this time lightly. A poignant sobbing greeted his ears.

He bent his head closer and said: "It's me. Don't be afraid. I'm Stirling—the Ice Pilot. I'm the one who was in the crow's-nest."

He strained his ears, and the sobbing ceased. A hand was on the latch; the door started to slide open.

"It's me," he repeated as the hand that pressed the door hesitated. "I'm all right," he added, with tired assurance. "I'm armed, and that sailor is taken care of—the one who insulted you."

The door slid open swiftly, and the girl stood framed in the aperture. Her hair was down her back, her wide eyes swollen from tears and distress.

He rested the rifle against his hip. "Are you all right?" he asked, sincerely. "Are you?"

"Yes—now, I am." The glance that lifted to his own was frank and shimmering with amazement. Stirling glanced over her shoulder full into a long cheval mirror, and recoiled as he looked at his own reflection. The oil and grease of the shaft alley, the week-old stubble of beard, the wan, red-rimmed eyes which shone from hollow sockets—these made a picture of desperate adventure.

"You'll have to excuse me," he said. "I didn't know I looked like this."

The girl smiled and extended her hand. "You came to me," she said, bravely. "That's what I wanted."

Stirling nodded and rubbed his chin with his palm, then turned and stared toward the curtain. Slim had rolled over and was hammering the cabin deck with his heels in an endeavour to escape the bonds around his wrists and elbows.

"I found him," said Stirling. "What do you say if we go in there—Miss—Miss——"

"Miss Marr—Helen Marr," she said, quickly, as she came gliding out of the door. "You see," she added, "I'm not a bit frightened—at you!"