the next day, while canolles was making his morning round, vibrac approached him and handed him a note and a key which had been brought to the fortress during the night by a strange man, who left them with the lieutenant of the guard, saying that there was no reply.

canolles started as he recognized the handwriting of madame de cambes, and his hand trembled as he broke the seal.

this is what the letter contained:—

"in my last note i gave you warning that saint-georges would be attacked during the night; in this, i warn you that saint-georges will be taken to-morrow; as a man, as an officer of the king, you run no other risk than that of being made prisoner; but mademoiselle de lartigues is in a very different situation, and the hatred which is entertained for her is so great that i would not answer for her life if she should fall into the hands of the bordelais. therefore persuade her to fly; i will furnish you with the means of flight.

"at the head of your bed, behind a curtain upon which are embroidered the arms of the lords of cambes, to whom ?le saint-georges formerly belonged,—monsieur le vicomte de cambes, my late husband, presented it to the king,—you will find a door to which this is the key. it is one of the entrances to an extensive underground passage which passes beneath the bed of the river, and comes out at the manor of cambes. persuade mademoiselle nanon de lartigues to fly through that passage—and, if you love her, fly with her.

"i answer for her safety upon my honor.

"adieu. we are quits.

"vicomtesse de cambes."

canolles read and re-read the letter, shivering with fear at every word, growing paler with every reading; he felt that a mysterious power, which he could not fathom, enveloped him, and directed his actions. might not this same underground passage, from his bedroom to the chateau de cambes, which was to serve to assure nanon's safety, serve equally well, if the secret were generally known, to deliver saint-georges to the enemy?

vibrac followed, upon the governor's expressive features, the emotions which were reflected there.

"bad news, commandant?" he asked.

"yes, it seems that we are to be attacked again to-night."

"the fanatics!" said vibrac. "i should have supposed we had given them a sufficient dressing-down, and were not likely to hear of them again for a week at least."

"i have no need to enjoin the strictest watchfulness upon you," said canolles.

"have no fear, commandant. probably they will try to surprise us, as they did before?"

"i have no idea; but let us be ready for anything, and take the same precautions that we took before. finish my round of inspection for me; i must go to my room; i have some orders to give."

vibrac touched his hat and strode away with the soldierly indifference to danger often exhibited by those whose profession brings them face to face with it at every step.

canolles went to his room, taking every possible precaution not to be seen by nanon; and having made sure that he was alone, locked himself in.

at the head of his bed were the arms of the lords of cambes, upon a tapestry hanging surrounded by a band of gold.

canolles raised the band, which was not attached to the tapestry, and disclosed the crack of a door. with the aid of the key which accompanied the viscountess's letter, he opened the door, and found himself confronted by the gaping orifice of a subterranean passage.

for a moment canolles was struck dumb, and stood motionless, with the sweat pouring from his brow. this mysterious opening into the bowels of the earth terrified him in spite of himself.

he lighted a candle and prepared to inspect it.

first, he descended twenty steep stairs, then kept on down a gentler slope farther and farther into the depths.

soon he heard a dull, rumbling noise, which alarmed him at first, because he could not think to what cause to attribute it; but as he went forward he recognized it as the roar of the river flowing above his head.

the water had forced its way through the arch in divers places at one time or another, but the crevices had evidently been detected in time and filled with a sort of cement, which became harder in course of time than the stones it bound together.

for about ten minutes canolles heard the water rolling over his head; then the noise gradually died away until it was hardly more than a murmur. at last even the murmuring ceased, to be succeeded by perfect silence; and after walking a hundred feet or more in the silence, canolles reached a staircase similar to the one by which he had descended, and closed at the top by a massive door which the united strength of ten men could not have moved, and which was rendered fire-proof by a thick iron plate.

"now i understand," said canolles; "she will await nanon at this door and help her to escape."

he retraced his steps beneath the river-bed, ascended the staircase, re-entered his room, replaced the gold band, and betook himself deep in thought to nanon's apartments.