"An attack of pleurisy, which carried him off in a few days. He hardly recovered consciousness before the end; and the horrible thing appears to have been that he was seen to make violent efforts, between his fits of delirium, to collect his thoughts and utter connected words. From time to time, he called his wife, looked at her in a desperate way and vainly moved his lips."

"In a word, he spoke?" said Lupin, cutting him short, for the "working"

at the lock was beginning to make him anxious.

"No, he did not speak. But, in a comparatively lucid moment, he summoned up the energy to make some marks on a piece of paper which his wife gave him."

"Well, those marks ... ?"

"They were illegible, for the most part."

"For the most part? But the others?" asked Lupin, greedily. "The others?"

"There were, first, three perfectly distinct figures: an 8, a 1, and a 3... ."

"Yes, 813, I know ... and next?"

"And next, there were some letters ... several letters, of which all that can be made out for certain are a group of three followed, immediately after, by a group of two letters."

"'APO ON,' is that it?"

"Oh, so you know! ..."

The lock was yielding; almost all the screws had been taken out. Lupin, suddenly alarmed at the thought of being interrupted, asked:

"So that this incomplete word 'APO ON' and the number 813 are the formulas which the grand-duke bequeathed to his wife and son to enable them to find the secret papers?"

"Yes."

"What became of the grand-duke's wife?"

"She died soon after her husband, of grief, one might say."

"And was the child looked after by the family?"

"What family? The grand-duke had no brothers or sisters. Moreover, he was only morganatically and secretly married. No, the child was taken away by Hermann's old man-servant, who brought him up under the name of Pierre Leduc. He was a bad type of boy, self-willed, capricious and troublesome. One day, he went off and was never seen again."

"Did he know the secret of his birth?"

"Yes; and he was shown the sheet of paper on which Hermann III. had written the letters and figures."

"And after that this revelation was made to no one but yourself?"

"That's all."

"And you confided only in Mr. Kesselbach?"

"Yes. But, out of prudence, while showing him the sheet of letters and figures and the list of which I spoke to you, I kept both those documents in my own possession. Events have proved that I was right."

Lupin was now clinging to the door with both hands:

"Weber," he roared, "you're very indiscreet! I shall report you! ...

Steinweg, have you those documents?"

"Yes."

"Are they in a safe place?"

"Absolutely."

"In Paris?"

"No."

"So much the better. Don't forget that your life is in danger and that you have people after you."

"I know. The least false step and I am done for."

"Exactly. So take your precautions, throw the enemy off the scent, go and fetch your papers and await my instructions. The thing is cut and dried. In a month, at latest, we will go to Veldenz Castle together."

"Suppose I'm in prison?"

"I will take you out."

"Can you?"

"The very day after I come out myself. No, I'm wrong: the same evening ... an hour later."

"You have the means?"

"Since the last ten minutes, an infallible means. You have nothing more to say to me?"

"No."

"Then I'll open the door."

He pulled back the door, and bowing to M. Weber:

"My poor old Weber, I don't know what excuse to make ..."

He did not finish his sentence. The sudden inrush of the deputy-chief and three policeman left him no time.

M. Weber was white with rage and indignation. The sight of the two men lying outstretched quite unsettled him.

"Dead!" he exclaimed.

"Not a bit of it, not a bit of it," chuckled Lupin, "only asleep!

Formerie was tired out ... so I allowed him a few moments' rest."