Within an hour after Pomperant's return to the camp, all the batteries on which the heavy cannon brought from Toulon had been mounted, opened fire upon that part of the ramparts where the breach had formerly been made. By nightfall a wide gap was made, and the cannonade then ceased.

At the same time the sappers, who had carried their works under the fosse after incredible toil, had reached the foundations of the walls. Before midnight the chamber of the mine was completed, and the barrels of gunpowder deposited within it; and Lurcy, who had been entrusted with the superintendence of this dangerous operation, brought word to Bourbon that all was ready.

“Let the mine be sprung, then,” replied Bourbon. “It will save some hours' work in the morning.”

On returning to execute this order, Lurcy was accompanied by Pomperant. After tracking the windings of the long gallery, which was lighted by torches fixed at various points, and crowded by soldiers, they at length reached the chamber of the mine. Having seen that all the arrangements were carefully made, and that the casks of powder were so placed that they could be simultaneously exploded, they were about to retire, when the stroke of a pickaxe was heard on one side of the excavation. They listened intently, and the sound was again plainly distinguished.

“The enemy are making a counter-mine,” said one of the sappers who was with them. “They are close upon us.”

As he spoke, the strokes grew quicker and louder.

“They are working hard,” remarked another sapper, with a grim smile. “But we shall soon check them.”

While this took place, a third sapper, who had been engaged in laying a train of powder communicating with the barrels, got up and said to Lurcy and Pomperant, “Retire, I pray you, messeigneurs. The train shall be fired as soon as you are out of danger.”

On this intimation, Lurcy and Pomperant hastily retreated to the first epaulment, which was placed on the outer side of the moat, and in which they could take refuge during the explosion. All the sappers accompanied them, except one man, whose business it was to fire the train.

On reaching the mouth of the epaulment, Lurcy called out to the man who was left behind—“Fire!”

On this the sapper knelt down and applied a lighted tow-match to the long train of powder. Both Lurcy and Pomperant watched the proceeding from the entrance of their place of refuge. In an instant the fiery line started on its terrible errand, and the sapper hurried off to the shelter of the epaulment.

Just at this moment, however, and while Pomperant was still watching the course of the burning train, he was startled by an unexpected occurrence. The whole of the wall of earth at the end of the chamber of the mine suddenly gave way, disclosing those who were engaged in making the counter-mine.

What was Pomperant's horror on discovering that the foremost of the party were no other than Marphise and Marcelline! Torches held by the Amazons in the rear fully revealed them to view. There they stood, pickaxe in hand, preparing to leap over the mass of earth into the chamber.

Horrified at the sight, Pomperant would have rushed towards them had he not been forcibly held back by Lurcy. The two Amazons seemed paralysed by terror, and unable to retreat.

“Back, on your lives!” shouted Pomperant, in extremity of anguish.

A giddiness seized him, and, unable to offer any further resistance, he was dragged into the epaulment by Lurcy.

At this moment the explosion took place with a terrific sound, and a shock like that of an earthquake. From the noises that succeeded, it was evident that a large portion of the wall, under which the mine had been laid, was overthrown.

In another minute all these appalling sounds ceased, and a silence like that of death succeeded.

Lurcy and Pomperant, with the sappers, rushed out of the epaulment. But they could not proceed many paces. The torch held by one of the men flashed on a terrible scene, and revealed the work of destruction. The farther end of the passage beneath the moat was blocked up with huge stones and rubbish, and rents having been made in the sides, the water from the moat was pouring in, the place being already half flooded.

“I have lost her!” exclaimed Pomperant, in accents of despair. “They must all have perished in that terrible explosion. Why did you not let me extinguish the train?”

“Had you made the attempt, you would only have thrown away your own life,” rejoined Lurcy. “But come away. You can do no good here.”

“I will not go till I have ascertained what has become of her,” cried Pomperant.

“Give yourself no further trouble, monseigneur,” remarked the sapper who had fired the mine. “Not one of those brave young women can have escaped. They are all crushed beneath those stones.”

“I would I had perished with her!” ejaculated Pomperant. And he reeled back, half fainting, against the side of the gallery.

Giving some hasty directions to the men, Lurcy took the arm of his friend, and led him away from the scene of destruction.

As they threaded the winding passages, their progress was impeded by parties of soldiers who were hastening from the place of arms to the farther end of the mine; but at last they issued forth into the open air.

As soon as Pomperant reached his tent, he threw himself on a couch in a state of complete exhaustion, while Lurcy hastened to inform Bourbon that the mine had been sprung.