Burton realised that as yet he had had to deal with only a small advanced guard. The fight would take on quite a different complexion when the main body now pressing forward came into action. There was no sign of irresolution in the enemy. Even though he should sweep the track twice or thrice with the machine-gun, they would then discover that his ammunition was expended, and three rifles would avail nothing against the numbers who would pour upwards to the assault. It was time to prepare to play his last card--to light the train which, after an unknown interval, would explode the dynamite and render the track impassable. The tower was doomed. If not carried by assault, it would be shattered as soon as artillery was brought to bear on it. But even though it were destroyed, and all in it, the destruction of the track would delay the enemy for many hours, and his object would be gained. He inferred, and rightly, as it proved, that the lull would continue until the enemy had come up in sufficient strength to burst through at all costs. But there was no time to spare, especially as so much uncertainty attended the action of the mine. Leaving the two Serbs to keep watch, Burton went below. Nuta was still knotting the lengths of cloth, but he saw at a glance that the coil she had completed would suffice. He made her understand by signs that she was to follow him to the cellar, carrying the revolver. The eager looks with which the prisoners met him bespoke their confidence that he had come to beg their intercession with victorious Bulgarians. They were immediately undeceived. "I am going to fire the dynamite," he said. "This place will no longer be safe for you. You must quit the tower. Follow my instructions to the letter. When you leave the entrance, you will cross the enclosure to the wall on the south side, climb it, and go as far along the track southward as you please. If you attempt to move in the opposite direction 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 is against ze law of nations. Zere shall be reprisals. You make var prisoners vork to blow up zeir allies; you----" "Nothing of the sort," Burton interrupted sharply. "You removed the dynamite for your own safety; you are at liberty to bring it back, and take the consequences. You must decide at once." This reduced the German to silence. "Was giebt es?" asked Schwartzkopf, evidently puzzled by the captain’s agitation. When Hildenheim had explained, the major came to a decision with great alacrity. It would be absurd to reject the chance of escaping with a whole skin. There was a short excited colloquy between the two Germans. Then Hildenheim sullenly announced their acquiescence, and they followed Burton and the woman up the stairs. When a passage had been opened in the entrance, the three prisoners made to issue together.