No amount of money would be too great to pay for the secret; America could not put her millions to better use.

But to buy the machine, it was necessary to find the inventor; and there seemed the chief difficulty. In vain was Lake Kirdall searched from end to end. Even its depths were explored with a sounding-line without result. Must it be concluded that the submarine no longer lurked beneath its waters? But in that case, how had the boat gotten away? For that matter, how had it come? An insoluble problem!

The submarine was heard from no more, neither in Lake Kirdall nor elsewhere. It had disappeared like the automobile from the roads, and like the boat from the shores of America. Several times in my interviews with Mr. Ward, we discussed this matter, which still filled his mind. Our men continued everywhere on the lookout, but as unsuccessfully as other agents.

On the morning of the twenty-seventh of June, I was summoned into the presence of Mr. Ward.

"Well, Strock," said he, "here is a splendid chance for you to get your revenge."

"Revenge for the Great Eyrie disappointment?"

"Of course."

"What chance?" asked I, not knowing if he spoke seriously, or in jest.

"Why, here," he answered. "Would not you like to discover the inventor of this three-fold machine?"

"I certainly should, Mr. Ward. Give me the order to take charge of the matter, and I will accomplish the impossible, in order to succeed. It is true, I believe it will be difficult."

"Undoubtedly, Strock. Perhaps even more difficult than to penetrate into the Great Eyrie."

It was evident that Mr. Ward was intent on rallying me about my unsuccess. He would not do that, I felt assured, out of mere unkindness. Perhaps then he meant to rouse my resolution. He knew me well; and realized that I would have given anything in the world to recoup my defeat. I waited quietly for new instructions.

Mr. Ward dropped his jesting and said to me very generously, "I know, Strock, that you accomplished everything that depended on human powers; and that no blame attaches to you. But we face now a matter very different from that of the Great Eyrie. The day the government decides to force that secret, everything is ready. We have only to spend some thousands of dollars, and the road will be open."

"That is what I would urge."

"But at present," said Mr. Ward, shaking his head, "it is much more important to place our hands on this fantastic inventor, who so constantly escapes us. That is work for a detective, indeed; a master detective!"

"He has not been heard from again?"

"No; and though there is every reason to believe that he has been, and still continues, beneath the waters of Lake Kirdall, it has been impossible to find any trace of him anywhere around there. One would almost fancy he had the power of making himself invisible, this Proteus of a mechanic!"

"It seems likely," said I, "that he will never be seen until he wishes to be."

"True, Strock. And to my mind there is only one way of dealing with him, and that is to offer him such an enormous price that he cannot refuse to sell his invention."

Mr. Ward was right. Indeed, the government had already made the effort to secure speech with this hero of the day, than whom surely no human being has ever better merited the title. The press had widely spread the news, and this extraordinary individual must assuredly know what the government desired of him, and how completely he could name the terms he wished.

"Surely," added Mr.