Lieutenant Potugin smiled.

"Ah Lum has been a bogey to them, truly, ever since Captain Kargopol walked into his trap. But I think we'll run the fox to earth this time. General Bekovitch will soon start the rounding up; and 'tis high time."

A half-company of Siberian infantry, including a few engineers, were seated on the rocks in the hills above the Ma-en-ho, engaged in a meagre luncheon of black bread and vodka. They had arrived early that morning by special troop train, in company with a sotnia of Cossacks, from Harbin. Their errand was to establish a temporary signal-station on a convenient hilltop. The hole for the signal-pole had been dug, not without difficulty, in the hard and frozen soil, and before the completion of the job was taken in hand, Lieutenant Potugin, in command of the working party, was allowing his men a short respite for rest and food. The Cossacks meanwhile were scouting in the hills beyond—a task they were by no means fond of,—and seeking a suitable place for the erection of a corresponding signal some miles distant, whence communication could be established with the height now occupied by the infantry.

Lieutenant Potugin was very popular with his men, largely because he never overworked them and was quite content when on duty to share their humble rations. He was seated now beside the sergeant, in the midst of the circle, munching his bread, and every now and then raising his field-glass to scan the surrounding heights. It was a fine morning; a breath of spring was already in the air, even in these heights; the atmosphere was clear, and the outlines of the country were sharply defined against the unclouded sky.

Over the shoulder of a low hill beneath him he could just see a stretch of the main railway line, some three miles away. The little branch line along which his train had come that morning was out of sight immediately below; but he expected every moment to see the empty train reappear on the main line. It was to return to Harbin; rolling stock was urgently needed on all parts of the system; and when his work was done Lieutenant Potugin was to report himself to General Bekovitch and join that officer's carefully-planned expedition against the Chunchuses. The branch line ended at a disused quarry which had been largely drawn upon when the main railway was under construction; and there was no telegraphic communication between the main line and the terminus of the branch—if, indeed, the latter could be said to have a terminus: it simply left off. The empty troop train would doubtless remain at the junction until it was signalled by trolley-car from Imien-po to proceed.

The sergeant, a famous raconteur, was telling a story, long-winded, not at all humorous, yet received by the men with shouts of laughter. Lieutenant Potugin smiled good-humouredly at the naïve amusement of the honest fellows, and once more idly scanned the panorama beneath him. In the far distance he saw a dense line of smoke lying flat in the still air, betokening a train travelling eastward at a high speed. He watched it with languid curiosity as it appeared in the open and vanished into cuttings in the winding valley of the river. It passed the junction, slackening speed, and then, to his surprise, pulled up. Distant though it was, he could distinctly see through his powerful glass a little knot of men hurrying from the train up the line. They disappeared for a time, apparently beneath a culvert. The circumstance awakened Lieutenant Potugin's curiosity; he watched with a certain eagerness for the men to reappear; one or two small groups could be seen against the snow, but a considerable time elapsed before the most of the men joined them and the whole party ran back to the train. Scarcely had they reached it when a cloud of dust rose high into the air above the bridge, and a few seconds later the sound of two dull explosions reached the lieutenant's ear, followed by miniature echoes from the rocks.

The lieutenant sprang up and gazed intently through his glass. The sounds had been heard by the men also; they turned their heads for a moment, but, seeing nothing, resumed their conversation. But Potugin stood as if stupefied. An attempt had been made to wreck the culvert; that was clear. But who were the wreckers? Were they Russians, cutting the railway to check pursuit by the Japanese? Surely the enemy was not already at Harbin? Accustomed as he was in this terrible war to sudden and startling movements, the lieutenant could not believe that the Japanese had made such strides. No, he thought; it was more likely to be a party of Japanese who had captured the train and were engaged on a wrecking foray. Such things had happened south of Moukden; a flying squadron might have evaded the Cossacks and made a daring attack on some inadequately protected train.

The train was moving forward. But what is that? It has stopped again; it is running back towards the stream. The madmen! Are they going to hurl themselves to destruction on the ruins of the culvert? Potugin's gaze is fascinated. Ah! he sees through it now; three carriages have left the rest of the train, which is again at a standstill; they are rushing down the gradient, faster, faster. Good heavens! they have crashed into the culvert, piling themselves one above another, and the sound comes to him like the breaking of some giant's crockery afar.

Then Potugin found his wits. Nothing in the whole course of the war had given the Russians so much anxiety as their railway. Depending on it for the rapid transit of reinforcements and munitions of war, they were constantly in nervous dread of this their sole communication with St. Petersburg being cut by Japanese or Chunchuses. The dreaded thing had happened. Fully realizing the situation, Lieutenant Potugin was prompt to act.

"Fall in!" he shouted.