So confident was he of the success of his scheme that when, after the single rail was removed and flung over the embankment, he again crowded on steam, his mind was occupied rather with the question of what should be done at the next station than with the prospect of further difficulties with his dogged pursuer. He was now approaching the place in the hills to which Ah Lum was to advance by forced marches, and whence he was to be prepared to dash across the line on receiving a message that the scheme had succeeded. Jack had already selected his messenger; the man was clinging to the rail of the engine, and only awaited the word to spring during a temporary slackening of speed and plunge into the hills.
The chosen spot lay between Pei-su-ho and Kao-ling-tzü, and had been minutely described by Ah Lum. Jack was glad that his anxieties appeared to be over, for the country flashed by so rapidly that he ran the risk of over-shooting the mark unless he could keep a good look-out. He was narrowly watching for the opening on his right when Hi Lo suddenly drew his attention westward. With greater alarm than he had yet felt, even when he first caught sight of the pursuer, he saw, scarcely a mile and a half behind him, the relentless enemy leaping along in his wake. He was half-way up a steep incline; the second train was rushing with wholly reckless speed down a steep straight gradient on which Jack, no longer fearing pursuit, had thought it desirable to clap on the brakes. All notion of going cautiously must now be abandoned. Amazed at the failure of his last effort to delay the pursuer, Jack set his men with desperate energy to pile up the furnace to its utmost capacity; and when he topped the hill, and the enemy was just beginning the ascent, he let the engine go at its own pace down the opposite side. He and his men had to hold on with both hands as they rounded another sharp curve; the wheels on the inside seemed to be raised from the track, the train keeping the rails only by the grip of the outside wheels. Jack held his breath as the panting engine plunged along; would it come safely on to the straight? Even in the excitement of the moment he solved as in a flash the mystery of the pursuers' escape from derailment, and he could have beaten his head for his thoughtlessness. The rail that had been lifted was an inside rail; rounding a curve the weight of a train going at speed is always thrown on the outer rail, which is raised above the level of the other. Either designedly or by accident the pursuing train had passed at full speed over the gap, its very speed proving its salvation.
Although there were many ups and downs, the general trend of the line was still chiefly on the up grade, and Jack found that while the enemy made as good timing as himself down the slopes, their more powerful engine gained rapidly wherever the track began to rise. As mile after mile was passed, the huts of the line guards at intervals of ten versts seeming like the milestones on an ordinary journey, the space between the two trains steadily diminished. Every now and again the pursuer was lost to view; but whenever it next came in sight it was always perceptibly nearer. The noble Alexander the Second rattled and groaned like a creature in pain; the working parts were smoking; some of the bearings were melting, and Jack dared not risk the perils of oiling. He knew that he was getting out of it every ounce of which it was capable, unless indeed he adopted the desperate expedient of screwing down the safety-valve, from which a dense cloud of steam was escaping. He glanced at the gauge—13 atmospheres; then his eye went backwards along the track—the pursuer was still gaining; he turned to look ahead, there was a long steep ascent to be climbed. The pace lessened to an alarming extent: puffing, panting, creaking, the engine toiled up a hillside on which the track could be seen rising for at least two miles. He must risk it.
Three minutes later, the valve now screwed down, he again glanced at the gauge—14 atmospheres. Bursting pressure, Jack knew, was calculated at five or six times the working pressure; but the Alexander the Second was an old engine, he doubted whether her boilers would stand anything like this strain.
For a time Jack's train drew away; but the gain was only temporary; the pursuers, he guessed, must have adopted the same desperate expedient. Gradually they crept up, while Jack alternately watched them and the track ahead, and the gauge, which now registered 15 atmospheres—the limit which it was constructed to indicate. Beyond this point he had no means of knowing how the pressure was increasing. The rapidity of his thoughts seemed to keep pace with the tremendous speed at which he was travelling. His mind worked with marvellous clearness; the minutes seemed like hours; he even found himself speculating which of the three risks was the greatest—derailment, capture by the Russians, or the imminent explosion of the boiler.
To look for the spot chosen for the despatch of his messenger was out of the question; it had probably been already passed. Jack felt that he had no longer any alternative; he must play what seemed his last card. The pursuing train was only half a mile behind on the steep upward track when at his order Wang Shih, at the risk of his life, uncoupled the rearmost of the three carriages. For a short distance it followed the rest; then it stopped, and began to run back at a pace that threatened to telescope at least one carriage of the oncoming train. A turn in the track hid both the detached carriage and the pursuer from sight; Jack listened with a beating heart for the sound of the collision, which he felt would be audible even above the thundering roar of his own train.
Lightened of part of its load, his engine was forging its way uphill at considerably higher speed. At one moment he thought he heard the expected crash, and it seemed that the move had been successful, for when next he obtained a fair view of the line behind, the enemy was not in sight. Alternating between compunction and elation, he ventured, the line being more level, to reduce speed until it was safe to drop his messenger, who must perforce find his way to Ah Lum. But the man had barely left the track when, to Jack's amazement, the indomitable pursuer reappeared. A glance showed him that it was pushing the discarded carriage before it. His move had been detected, probably before the cast-off carriage began its backward journey; the pursuing engine had been able to reverse in time; chased and overtaken by the runaway carriage, the train had no doubt been badly bumped, but not with force enough to cause any serious damage. Now, to all appearance, it was following the quarry at the same breakneck pace as before. Jack felt a glow of admiration for the wary Russians, who showed themselves so intent to mark his every move, so quick to take measures to defeat it.
His mouth hardened as he watched the pursuer gaining upon him yard by yard. He knew that the pressure must now be enormous; would the boilers stand the strain? Yet in spite of all he was steadily being overhauled. Yard by yard the gap lessened. Nothing but an accident could now prevent him from being overtaken; his only course seemed to be to stop before the enemy was too close, reverse his engine, and with his men take to the hills. But then he reflected with a kind of agony that the task he had set himself was even yet only half done. There was no longer, indeed, any chance of Ah Lum's retreat being cut from the west; but the Russians could still despatch a force from Ninguta in ample time to check the Chunchuses before they got across the railway; and if they were once checked, the forces behind would at once close in and crush them. While, therefore, the slightest hope remained, Jack resolved to cling to his train; but he gave his men orders to jump clear at a moment's notice. They must now be very near to Kao-ling-tzü: if they failed to cut the line there the race was clearly run, for a warning would certainly be flashed over the wire to the next station at Han-ta-ho-tzü, giving ample time for preparations to be made to meet him. He was in a bath of sweat; his throat was parched; his limbs were trembling; but collecting all his forces, he watched the gauge and grasped the lever.
There remained, he clearly saw, one small chance, and only one. If there happened to be a train at Kao-ling-tzü side-tracked in obedience to his instructions, it might be possible—how long would it take?—to interpose it between himself and his pursuers. There would be a minute, nay, less than a minute, to gain possession of it and set it in motion. Could he increase the margin? Yes; by detaching the saloon, now the rearmost carriage, and crowding the whole of his men and the two prisoners into the single carriage in front. The enemy had all along shown himself so alert that he would doubtless be on the look-out for such a move; there was no longer any likelihood that it would end the chase; but at least it would check the pursuer's progress, forcing him to stop or reverse. Even if it caused the delay of only a few seconds, it was worth attempting; a few seconds might make all the difference.
The station was already in sight when, the transference of men having been quickly effected, Wang Shih broke the couplings and left the saloon solitary upon the line. Looking with blood-shot eyes ahead, Jack saw—and his labouring heart leapt at the sight—not one, as he had hoped, but two trains, one behind the other, completely filling a siding, where they were halted to allow General Bekovitch's expected train to pass.