VI

  There was little conversation during the night. Every member of theparty was so fatigued that, when not on watch, he slept heavily.Enderby alone was wakeful, from the pain of his wounds, and he addressedBurton only in occasional whispers, lest Hildenheim should overhear him.The two German officers conversed in their own tongue, pitching theirvoices low; but neither of the Englishmen understood German. Atintervals the distant boom of heavy guns indicated that a night attackwas in progress somewhere to the east.

  Before daybreak Burton roused his companions. It was necessary to laytheir plans in readiness for the expected advance of the Bulgariantroops. In company with old Marco, Burton took stock of theirresources. They had the weapons of their enemies--ten rifles with abouttwo thousand rounds of ammunition, three revolvers with thirty roundsapiece, their own machine-gun with three ammunition belts. There was aplentiful supply of provisions, but little fodder for the horses.Burton was tempted to make good their escape while there was yet time;but after a few moments' reflection he reverted to his purpose ofdelaying the enemy's advance to the last minute of endurance. Thetower, commanding the narrow track, offered great advantages to thedefence; and guessing that the Bulgars' advance guard would consist ofcavalry unprovided with artillery, he hoped to be able to hold his ownuntil help arrived.

  The first necessity was to inform the British general of the anticipatedflank attack.

  "Your grandson can ride a horse?" he asked old Marco.

  "Tchk! The boy sat a horse as soon as he could walk," replied the oldman, with a laugh.

  "Then I want to send him with a note to our men. Will you instructhim?"

  He wrote in his pocket-book a note explaining that Captain Enderby,wounded, with himself and two Serbians, both slightly wounded, wereholding a tower in the hills some ten miles south of Strumitza. Theyexpected to be attacked by a Bulgarian column moving south-west acrossthe hills to cut the British line of retreat, and would hold out as longas possible. Their greatest need, if attacked in force, would beammunition; and he pointed out that the position would be hopelessagainst artillery. Tearing the leaf out, he folded it, addressed it to"Any British Officer," and gave it to Marco, who tucked it inside histunic. As soon as dawn glimmered the boy mounted one of the horses andset off, disappearing into the mist.

  "We had better take the horses out," Burton suggested. "They will onlyhamper us here; besides, we may as well keep them alive if we can."

  On old Marco agreeing, Milosh led the horses to the dell where the oxenhad been tethered overnight, tied them together, and hobbled them toheavy fragments of rock. Meanwhile the others strengthened the cartbarricade, blocked up the entrance to the tower with stones, brokentimber, and other rubbish, and placed the machine-gun at a narrow windowcommanding the track. Then Burton climbed the ladder leading to the topof the tower, to examine the country through his glasses; but the heavywhite mist hid everything from view. Guns boomed incessantly; thesounds were little louder than they had been in the night. It was clearthat the British retirement was being conducted without hurry.

  When he came down he found that Nuta had got ready a meal for his partyand the three prisoners. With these latter, since his arrival at thetower, he had had no conversation. Now, however, Captain von Hildenheimaddressed him.

  "Major Schwartzkopf demands to know vat you do," he said. "Ze majorshpeak no English."

  Burton glanced at the elder German, who stared at him with mingledinsolence and sullenness.

  "Tell him that I hope before the day is out to hand him over to theBritish provost-marshal," he said.

  Hildenheim translated. The major gurgled out a rapid sentence.

  "You mistake," Hildenheim went on. "Major Schwartzkopf vish to know vatyou do here."

  "That is my business. If the major has patience he will see."

  The Germans talked together, and Burton gathered from their smiles thatthey supposed him ignorant of the Bulgarian advance, and flatteredthemselves that the tables would soon be turned on him.

  When breakfast was finished, Marco asked Burton to accompany him to thechamber below.

  "Twenty years ago," he said, "when I was here, we kept a few prisonersin a cellar below the floor. Shall we not place our prisoners therenow, for safety's sake?"

  "Let us have a look at it," Burton returned.

  Scraping away the litter of hay, earth, and fragments of wood from acorner of the floor, Marco disclosed a trap-door. They lifted this, andBurton descended a short ladder, Marco following him with an improvisedtorch. They found themselves in a shallow cellar, stuffy but dry.

  "What is this?" exclaimed Marco, pointing to a number of small woodenboxes ranged along one wall. "They were not here in my time."

  The boxes were thickly covered with dust, and had evidently been longundisturbed. Burton carefully prised up the lid of one of them.

  "It is full of sticks of dynamite!" he said, astonished. "A strangefind, upon my word!"

  "'A STRANGE FIND, UPON MY WORD!'"]

  "And look!" added Marco. "There is a tunnel--that was not here either."

  In one of the walls was an opening about four feet high. Entering this,the two men groped their way along a straight tunnel just wide enoughfor them to pass in single file.

  "This must have been made by the Greeks when they held the tower," theold man continued.

  "For what purpose? There's nothing in it."

  "But there is the dynamite in the cellar behind. I think the tunnelmust have been intended for a mine."

  "To blow up something outside? Let us see in what direction it goes."

  A glance at his compass showed him that the tunnel ran towards thenorth-east.

  "It is plain," said Marco. "Here at the end we may be standing beneaththe track. The Greeks intended to blow it up. I suppose the necessitypassed when the Turks retreated, and the dynamite was left here andforgotten. Perhaps the Greeks who made the tunnel were killed in thefighting afterwards."

  "Well, this may be a lucky find for us. We must see if it does endbeneath the track."

  Measuring his paces as they returned to the cellar, he went up, andcounted an equal number from the doorway of the tower, following thedirection of the tunnel as nearly as he could judge it. Thethirty-second pace brought him to the wall; there were still nine moreto take. At the forty-first he arrived at the centre of the track.

  "You were right," he said; "the intention was clearly to have a means ofblowing up the track. As you say, an explosion just there would make itimpassable. This may be a lucky find for us, my friend. We must removethe dynamite to the end of the tunnel, and make some sort of fuse."

  They returned to the tower. It was now half-past nine, the mist wasthinning, and before taking in hand the preparation of the mine, Burtonthought it well to make another survey from the top of the tower. WithMarco he climbed the ladder. Even with the naked eye he was able tosee, winding like a serpent across the white plain, a long column oftroops, its rear merging into the mist. Through his glasses hedistinguished its composition. In advance of the main body of infantryrode squadrons of cavalry. Here and there appeared files of pack-mules.He handed the glasses to Marco, whose face gloomed as he watched theunending stream.

  "The mules carry mountain guns," he said. "That's bad. They are comingon quickly, too. We shall not have time to prepare our mine."

  But as they went down again, to make final preparations for meeting theimpending attack, an idea occurred to him. Taking Marco to the lowerfloor, he said in English, loud enough to be heard by the prisonersabove--

  "A bomb would blow us all to smithereens. I had no idea there was somuch dynamite there."

  The Germans instantly rose to the bait. They could be heard in exciteddiscussion above. Waiting a few minutes to allow his words to producetheir full effect, Burton returned to the upper room. The officersbroke off their conversation and looked at him uneasily.

  "I beg your pardon,
sir," said Hildenheim at length, hesitatingly. "Youshpeak of dynamite?"

  "I did, yes--there is a considerable quantity in the cellar below."

  Looking very grave, Hildenheim translated to his companion, whose alarmfound vent in impassioned volubility.

  "Major Schwartzkopf protests viz indignation," Hildenheim went on. "Veare prisoners--so; but ze law of nations do not permit zat prisoners beconfined in a place of danger."

  "Danger, gentlemen! It was you who chose this place. What danger doyou anticipate?"

  "Our allies ze Bulgars zis vay come. Not understand? Zey attack zisplace. Ve sit on high explosive below; ze Bulgars shoot high explosiveabove; ve are blowed to--vat you call it?--schmiddereens!"

  "Surely your allies love you too well; they will not subject you to suchrisks."

  "I know not so much about zat. Zey love us--yes; but if it is zeir dutyzey blow us up all ze same."

  "We shall all be in the same boat, then. But perhaps you have somethingto suggest?"

  "It is ze law of nations zat you keep us safe."

  "You are quite safe so far as we are concerned. Obviously I cannotremove you. If your friends shell us--well!"

  "But you can remove ze dynamite. You can take it out, inter it, shuckit into--vat you call it?--a gully."

  "We haven't time for that. But I have an idea. There is a long tunnelleading from the cellar. If you and your companions care to carry thedynamite to the farther end of the tunnel, it will be out of harm's wayso far as the tower is concerned."

  "Zat is not ze vork of German officers."

  "No; quite so. If I were you I wouldn't do it. But, as you may havegathered, I intend to hold the tower as long as I can. Your cavalry isalready on the move. It will not be long before they attack. If youcare to remove the dynamite, you may stay in the cellar until--until Ifetch you out. Otherwise you will remain here."

  The Germans consulted.

  "Ze Herr Major agree, viz protest," said Hildenheim presently.

  "Agrees! To what?"

  "To move ze dynamite--vat you ask."

  "I beg your pardon, I ask nothing. You will do as you please. I saidif I were you----"

  "Ach! Ze Herr Major agree all ze same," interrupted Hildenheim,eagerly.

  "Very well."

  The Germans struggled to their feet.

  "You shall unbind our arms," said Hildenheim.

  "When you are in the cellar. Watch your footing as you go down."

  He preceded them down the stairs. When the three men were in the cellarhe left them his torch to work by, instructing them to carry the boxesto the end of the tunnel.

  It was necessary to devise a train for exploding the dynamite at thepinch of necessity. Having no gunpowder this was a difficulty untilMarco hit on a method. He bade Nuta bring some cotton cloths and somejars of grease that were among their belongings in the cart. The clothshe asked her to tear up into thin strips, and then to soak thoroughlywith the grease. By knotting these strips together she could make, hehoped, a match as long as the tunnel.

  There was no time to test it, or to judge how quickly it would burn.Scarcely ten minutes after the woman had begun her task Burton saw, fromthe loophole at which the machine-gun had been placed, the head of theenemy column appear on the track within effective rifle range. Itconsisted of a half-troop of cavalry, and was moving with cautiousslowness. In another minute it came to a halt. Two officers in frontheld a consultation. One of them peered through his glasses at thesilent tower. Their attitude suggested uncertainty. The lack ofsignals from the tower must have apprised them that their friends werenot in possession of it; but the information conveyed by the men who hadescaped overnight was necessarily vague, and they were ignorant whetherthe position was held by their foes, or had been abandoned.

  At the window, but out of sight of the enemy, Burton and the two Serbswatched them keenly. Enderby had been placed at the remote end of theroom, behind a barricade of timber, accoutrements, and rugs. In the lastfew moments Burton had discussed with him whether it would be well toopen a parley with the enemy, and announce his intention of disputingtheir passage.

  "My advice is to the contrary," said Enderby. "Deeds, not words. Ashot will tell them all you wish them to know."

  The consultation on the track came to an end, and the horsemen began tomove forward slowly. Two of them, one apparently an officer, rode alittle in advance of the rest. When they were still about half a miledistant, Marco raised his rifle to his shoulder and fired. Apparentlyhe missed, for the two men instantly threw themselves from their horsesand took cover among the rocks at the side of the track. A bugle rangout, and all down the column, as far as it was in sight, the troopersdismounted, left their horses, and advanced up the track on foot byshort rushes from one patch of cover to another.

  "What will they do?" Burton asked himself. He tried to put himselfmentally in their position. All the information they could have wasthat the tower was in enemy hands. They could not know who its captorswere, or how many they numbered. No doubt they would suppose that thepatrol had fallen to a superior force, but they would infer that thisforce was a comparatively small one, since it was already clear that noattempt was to be made to dispute their passage on the track itself.Their natural course would be to feel the strength of the garrison, andperhaps to refrain from throwing themselves against a strong defensiveposition until they had brought up guns to bombard it. The wild andrugged nature of the ground made rapid movement difficult, and Burtonhoped that the inevitable delay would not only enable the British Armyto secure its retirement, but would also give time for the dispatch of alight force to bring off himself and his party. The latter event he didnot count on; it might prove to be impracticable; in that case he couldonly look forward to the ultimate capture or destruction of the tower.It was his resolve to hold up the enemy till the last possible moment;if surrender were then necessary to save Nuta and Captain Enderby, hewould at least have the satisfaction of duty well done.

  Up to the present Marco's shot had been the only one fired. The twoSerbs, if left to themselves, would have aimed again and again at theBulgars, of whom they caught glimpses as they darted from rock to rock.But Burton prevailed on them to withhold their fire.

  "They don't know exactly how we are placed," he said to Marco, "and wemay as well keep them ignorant as long as possible. They are bound toleave cover if they mean to attack us; then will be our chance."

  The position gave incomparable advantages to the defence. Standing on aspur of the hillside, the tower could be assailed only from the track;its rear face overhung a precipitous cliff which not even a goat couldscale. For more than a hundred yards from the tower the track waswholly devoid of cover; the declivity on the one side and the highjagged ground on the other equally forbade an encircling movement.Burton's hope grew high as he weighed the chances for and against him.

  The enemy had crept up to within about three hundred yards of the tower.The next fifty yards of the track were exposed, then there was a breakin the bank in which they could find cover among low boulders andstunted bushes. It was at this point that they would first come insight of the wall surrounding the tower enclosure. Burton concludedthat as their mission was urgent, they would not wait the arrival oftheir artillery, which no doubt they had sent for at the first alarm,but would dash along the exposed portions of the track, shelterthemselves temporarily below the wall, and then endeavour to carry theposition with a rush. The gateway was blocked by the cart, but the wallcould easily be scaled, and the slender defences of the tower entrancewould yield in a few minutes. It was of prime importance, therefore,that the enemy should be prevented from reaching the wall. The track waswide enough for four or five men to move abreast. By means of themachine-gun, Burton could mow the enemy down if they advanced in mass;but having very little ammunition for it, he had decided to use it onlyas a last resource. In the early stages of the impending action he mustdepend on rifle fire, and he realised that, with no more
than threerifles, a great deal depended on the extent to which the enemy could beintimidated. Personally he was at a disadvantage in respect of hisunfamiliarity with the Bulgarian rifle. Marco had explained to him thesighting arrangements, which were adjusted to the metre scale; but herecognised that his first shots would be experimental. At short rangehe could hardly fail of success.

  Some minutes passed; the enemy gave no sign of movement.

  "Keep your eye upon them, while I go and see how the prisoners aregetting on with their work," said Burton to Marco.

  He went down to the cellar, observing on the way that Nuta had completeda large coil of the cotton rope. The Bulgar was staggering into thetunnel with the last of the boxes of dynamite. Hildenheim was donninghis tunic, which he had stripped off for the sake of ease in working.From the coolness and the unsoiled appearance of Major Schwartzkopf,Burton inferred, with secret amusement, that that officer had not puthimself to any exertion.

  "I zink I hear a shot, sir," said Hildenheim.

  "I thought so too," rejoined Burton. "But we are not engaged with yourfriends yet, and as I see that all the dynamite is removed, you are safehere--for the present."

  "So! I know ze Bulgar language. Ven our allies haf ze tower taken, Ivill haf much pleasure to--vat you call it?"

  "Interpret for us? Thank you, captain. I am sure you are anxious to beuseful."

  The dull reports of two rifle-shots recalled him. As he closed down thetrap-door, he heard Schwartzkopf guffaw. Springing up the stairs herushed to the window, where the Serbs were now firing steadily, seizedhis rifle, and looked down the track. A small party of the enemy hadbroken cover, and were rushing uphill in irregular formation. Severalhad already fallen; one dropped to Burton's first shot; but the restgained the cover of the stunted bushes before mentioned.

  "How many have got through?" asked Burton.

  "About half-a-dozen," Marco replied.

  "They haven't answered your fire?"

  He had hardly spoken when a hail of bullets pattered on the stone walls.Some had come from the advanced party in the bushes, some from theircomrades concealed farther down the track. One flew through the window,and struck the wall a few feet above Enderby's head. The three men drewback.

  "It is clear they have discovered where we are firing from," saidBurton. "We had better give them the next shots from the roof. Thereare loopholes in the parapet."

  They climbed up the ladder, and, kneeling behind the parapet, peeredthrough the loopholes. For some minutes the enemy continued to fire atthe window without exposing themselves. Presently, under cover of theirshots, a second party, larger than the first, emerged from the rocks fardown the track, and ran up to join their fellows hidden among thebushes. Instantly the three men opened fire; one after another theBulgars fell, but eight or nine reached shelter in safety. The enemy'sfire redoubled in violence; apparently they supposed that the defenderswere shooting both from the window and from the roof, for Enderby calledup that bullets were flying into the room, and at the same timesplinters of stone were struck from the parapet.

  Suddenly the firing ceased. Burton, looking through his glasses, sawreinforcements hurrying up along the track far below. Clearly the attackwas to be pressed, and the worst was yet to come. So far he was wellsatisfied. The enemy had been held up for more than an hour; everyminute gained might be of priceless service to the British forces.Every now and again the dull boom of artillery from the south told himthat his comrades were still fighting a rearguard action against heavyodds. To prevent the enlargement of those odds was worth any sacrifice.

  Burton realised that as yet he had had to deal with only a smalladvanced guard. The fight would take on quite a different complexionwhen the main body now pressing forward came into action. There was nosign of irresolution in the enemy. Even though he should sweep thetrack twice or thrice with the machine-gun, they would then discoverthat his ammunition was expended, and three rifles would avail nothingagainst the numbers who would pour upwards to the assault. It was timeto prepare to play his last card--to light the train which, after anunknown interval, would explode the dynamite and render the trackimpassable. The tower was doomed. If not carried by assault, it wouldbe shattered as soon as artillery was brought to bear on it. But eventhough it were destroyed, and all in it, the destruction of the trackwould delay the enemy for many hours, and his object would be gained.

  He inferred, and rightly, as it proved, that the lull would continueuntil the enemy had come up in sufficient strength to burst through atall costs. But there was no time to spare, especially as so muchuncertainty attended the action of the mine. Leaving the two Serbs tokeep watch, Burton went below. Nuta was still knotting the lengths ofcloth, but he saw at a glance that the coil she had completed wouldsuffice. He made her understand by signs that she was to follow him tothe cellar, carrying the revolver.

  The eager looks with which the prisoners met him bespoke theirconfidence that he had come to beg their intercession with victoriousBulgarians. They were immediately undeceived.

  "I am going to fire the dynamite," he said. "This place will no longerbe safe for you. You must quit the tower. Follow my instructions tothe letter. When you leave the entrance, you will cross the enclosureto the wall on the south side, climb it, and go as far along the tracksouthward as you please. If you attempt to move in the oppositedirection you will instantly be shot. That is quite clear?"

  Hildenheim's looks had grown blacker and blacker as Burton spoke.

  "It is a trick!" he burst out in a voice hoarse with rage. "It isagainst ze law of nations. Zere shall be reprisals. You make varprisoners vork to blow up zeir allies; you----"

  "Nothing of the sort," Burton interrupted sharply. "You removed thedynamite for your own safety; you are at liberty to bring it back, andtake the consequences. You must decide at once."

  This reduced the German to silence.

  "Was giebt es?" asked Schwartzkopf, evidently puzzled by the captain'sagitation.

  When Hildenheim had explained, the major came to a decision with greatalacrity. It would be absurd to reject the chance of escaping with awhole skin. There was a short excited colloquy between the two Germans.Then Hildenheim sullenly announced their acquiescence, and they followedBurton and the woman up the stairs. When a passage had been opened inthe entrance, the three prisoners made to issue together.

  "Not so fast--one at a time, if you please," said Burton, anxious not toleave the tower himself. "The major first; turn to the right, that'syour way. The woman will escort you."

  At another time he might have been amused at the sight of the Germanhastening towards the wall with an effort to maintain his dignity, Nutafollowing with pointed revolver a couple of yards behind. But thesituation was too tense for amusement. He was on thorns; at any momentwarning shots might recall him to his post, and the mine had still to becompleted. The instant the Bulgar, last of the three, reached the wall,Burton hurried into the cellar. He laid the cotton train on the floorof the tunnel, kindling its nearer end. At the farther end he upturnedthe open box of dynamite, placed a few cartridges at the extremity ofthe train, and packed the remaining boxes closely one upon another, sothat the space between the floor and the roof was completely blocked.Then with feverish haste he scraped up loose earth from the floor, anddug stones out of the wall with his knife, and heaped them up againstthe boxes, so as to minimise the effect of the explosion towards thecellar. On his return he saw that the cotton appeared to be burningsatisfactorily, and regained the roof of the tower after an absence oflittle more than twenty minutes.

  The situation had apparently not changed. All was quiet. None of theenemy in the vicinity of the tower were in sight, but the columns weresteadily rolling up the track in the far distance. A little later,however, there was a sudden rush from behind the rocks, accompanied by ahot fusillade. Bulgarian infantry swarmed up the track, and though manyof them fell to the three rifles, many more got through, stumbling overthe bodies of t
he fallen, and joined their comrades in the shelter ofthe bushes. Nuta had come up, and as the rifles became hot, shereplaced them with fresh weapons.

  The enemy advanced in an unending stream for five or six minutes. Thecrackle of rifle shots mingled with shouts and screams. Then at theblast of a whistle all movement ceased.

  Burton calculated that at least sixty men had run the gauntlet and werenow waiting among the bushes. Only about a hundred yards of open trackseparated them from the wall of the enclosure. To check the coming dashwith three rifles would be impossible. Would the explosion in thetunnel happen in time? He dared not go below again to see how the trainwas burning, nor could any one else be spared. Suppose the mine failed?The rush must be checked somehow; nothing but the machine-gun wouldavail.

  Leaving the Serbs on the roof, Burton went down into the room, andplaced himself at the gun.

  He had not long to wait. A whistle sounded shrilly. The men dashedfrom the cover of the bushes and poured up towards the tower, shoutingand cheering. Behind them their comrades opened fire from the rocks.Burton held his hand for a few seconds. Then, when the foremost rankhad covered about half the distance, the machine-gun rapped out a hailof bullets. In a few seconds the track was swept clear as by aninvisible scythe.

  Silence fell again. It was clear that the enemy had not reckoned with amachine-gun, for though, taking advantage of the charge, another body ofmen had rushed up to the bushes from the rear, they made no attempt toadvance farther.

  Minute by minute passed. Except for occasional sniping, the enemy tookno action. But the lull seemed ominous, and Burton remained keenly onguard, keeping a look-out from behind the shield of the machine-gun.

  "I don't like it," he said to Enderby once. "There isn't much doubt thatthey have sent word to their gunners, and we shall soon have shellshurtling upon us. There may be just time to carry you down and put youin safety beyond the tower."

  "Nonsense!" Enderby returned. "It makes me sick to be idling here. Iwon't go and keep your Germans company. My arms are sound enough, and,hang it all! I won't stand this any longer. Lift me out, and give me arifle."

  "No, no! Anything rather than that. At this window you'd be potted to acertainty. Perhaps it's better as it is, for if you were outside, andthe rest of us were smashed, you couldn't get away."

  "And I'd rather peg out than fall a prisoner to those German-ledBulgars. Don't worry, old chap!"

  "That wretched mine must have failed," said Burton, presently. "Nutamust go and relight the train."

  But just as he was rising to call her, he noticed something far down thetrack that caused him to drop back again.

  "They're smuggling a machine-gun into position!" he cried.

  He had caught a glimpse of the barrel projecting over a ledge of rock.With instant decision he trained his own gun upon it, and before itcould open fire, he pumped out a hail of lead that struck it from itsposition, and the men serving it, in spite of their shield, were killedor disabled either by direct shots, ricochets, or splinters.

  "One belt empty!" he said, as he replaced it with a full one. "ByGeorge! Now we're in for it!"

  He had heard the characteristic scream of a shell. Immediatelyafterwards there was a terrific explosion, and he saw a tall column ofsmoke, stones, and dust shoot into the air from the rocks not twohundred yards away. In another half-minute another shell exploded, alittle nearer.

  "They must be 'phoning the range," he said. "Look here, Enderby, I mustget you out of it. I can't leave the machine-gun now, but the Serbsmust carry you away. Marco Kralevich!" he shouted.

  The old man hurried down.

  "They'll have the range in a few minutes," said Burton. "I want you andyour friend to carry Captain Enderby out along the track yonder, towardswhere the prisoners are. Take your daughter, too. When you come back,go down into the cellar and relight the train; it must have gone out.They will smash the tower; the only chance of holding them up is toexplode the mine. Make haste, for Heaven's sake!"

  Marco summoned Nuta and Milosh from the roof. They lifted Enderby, andwere half-way down the stairs with him when the Bulgarian gunners madetheir first hit. A shell carried away a corner of the parapet. Thetower shook under the explosion, and the falling masonry plunged intothe enclosure, raising a dense cloud of dust. Burton trembled for thesafety of his friends, but his thoughts were taken from them by arenewed movement among the enemy. Immediately after the crash, the menconcealed in the bushes sprang out, and dashed forward with a cheer.They would have been wiser to wait. Burton saw them indistinctlythrough the dust, but he had the range to a yard, and again they meltedaway under his withering fire.

  Shells were now bursting around the tower. There was another crashabove; fragments of stone fell into the room, striking Burton in manyplaces. It was a moment of racking anxiety. He dared not leave the gununtil the track had been destroyed, yet the tower might crumple downupon him. His ammunition was running short--would Marco get back intime? Even if he relit the train, would the flame reach the explosives?And at that crisis he nerved himself for what must be regarded as asupreme act of self-sacrifice. If all else failed, at the last momenthe must go himself into the cellar, and fire into the charge.

  Deafened by the explosions that now recurred every few seconds,smothered in dust, struck by fragments of stone, half choked by fumes,he still held his place at the window. The enemy had learnt a lesson.They kept out of sight. Before long the guns would have done theirwork, and when the tower was in ruins the way would be clear.

  "They won't charge again till we're smashed," he thought. "Now for it!"

  Taking his rifle, he hurried down the stairs. At the trap-door hehalted a moment. He knew the risk he was about to run. His work in thetunnel had been so hurried that the backward force of the explosioncould not be wholly checked. He was taking his life in his hands; butit was the last hope. He gathered himself together. His foot was on thefirst step when he was brought to a halt by a rifle shot below. Thenext instant he was hurled back by a terrific concussion, and fell, animmense noise dinning in his ears. For a moment he lay dazed.

  "Marco must have done it!" he said to himself as he staggered to hisfeet.

  Down into the cellar he sprang, gasping in the noisome fumes. Hiselectric torch, still gleaming, lay on the floor. Near the mouth of thetunnel he saw the heroic old Serb prostrate. He rushed to him, stoopedover him. Was he yet alive? Burton could not tell. Exerting almostsuperhuman strength he managed to hoist the big man to his back, andstaggered with him across the cellar, up the steps, and across thefloor. Almost broken down under the weight of his burden, he was justreaching the entrance when there was an appalling crash. The towertottered and collapsed, and the two men fell together.

  A PERILOUS MOMENT]