"Not so fast--one at a time, if you please," said Burton, anxious not to leave the tower himself. "The major first; turn to the right, that’s your way. The woman will escort you." At another time he might have been amused at the sight of the German hastening towards the wall with an effort to maintain his dignity, Nuta following with pointed revolver a couple of yards behind. But the situation was too tense for amusement. He was on thorns; at any moment warning shots might recall him to his post, and the mine had still to be completed. The instant the Bulgar, last of the three, reached the wall, Burton hurried into the cellar. He laid the cotton train on the floor of the tunnel, kindling its nearer end. At the farther end he upturned the open box of dynamite, placed a few cartridges at the extremity of the train, and packed the remaining boxes closely one upon another, so that the space between the floor and the roof was completely blocked. Then with feverish haste he scraped up loose earth from the floor, and dug stones out of the wall with his knife, and heaped them up against the boxes, so as to minimise the effect of the explosion towards the cellar. On his return he saw that the cotton appeared to be burning satisfactorily, and regained the roof of the tower after an absence of little more than twenty minutes. The situation had apparently not changed. All was quiet. None of the enemy in the vicinity of the tower were in sight, but the columns were steadily rolling up the track in the far distance. A little later, however, there was a sudden rush from behind the rocks, accompanied by a hot fusillade. Bulgarian infantry swarmed up the track, and though many of them fell to the three rifles, many more got through, stumbling over the bodies of the fallen, and joined their comrades in the shelter of the bushes. Nuta had come up, and as the rifles became hot, she replaced them with fresh weapons. The enemy advanced in an unending stream for five or six minutes. The crackle of rifle shots mingled with shouts and screams. Then at the blast of a whistle all movement ceased. Burton calculated that at least sixty men had run the gauntlet and were now waiting among the bushes. Only about a hundred yards of open track separated them from the wall of the enclosure. To check the coming dash with three rifles would be impossible. Would the explosion in the tunnel happen in time? He dared not go below again to see how the train was burning, nor could any one else be spared. Suppose the mine failed? The rush must be checked somehow; nothing but the machine-gun would avail. Leaving the Serbs on the roof, Burton went down into the room, and placed himself at the gun.