“I was interested, once, in a forgery case in which you were employed to detect the criminals, by the examination of several handwritings which were given you. You accused a highly respectable fellow-citizen, to the astonishment of everybody, and convicted him, too. I, whom he had employed as an agent in some transactions, but who did not appear in any manner in the case, saw you in the court-room once or twice. I accidentally found out that you were a secret agent of the detective police. When I saw you here, playing the scientific gentleman, my conscience was not so easy as to blind me. I saw the game, and what was at stake. I had the choice between my own safety or yours. I wasn’t so self-denying as to decide in your favor, and so—”

“You visited my room last night.”

“Yes. But, on second thought, I decided that to-day would give me the better opportunity. Had you waited a second longer, your friends would have had a hard time tracing your fate. An excuse to my father-in-law, that you had returned to Acapulco without stopping, by a nearer route, would have ended inquiry here.” He set his teeth, as he concluded, unable to conceal how much he regretted that this convenient dénouement had been interrupted. “Was it chance caused you to turn?” he continued, after a moment’s silence.

“It was watchfulness. I thought I saw murder in your eyes once before, to-day, when I met them suddenly; but as I believed myself unknown to you, I could hardly credit my own impression. It grew upon me, however, as we proceeded, and ‘by the pricking of my ribs,’ I turned in time to prevent the compliment you were about to pay me. But this is wasting time. Write what I expect of you. I shall permit no lies. I can tell when I see one, or hear one. If you say any thing which is not true, I shall make you correct it.”

Coerced by the eye which never ceased to watch his slightest movement, and by the revolver held in range of his breast, the reluctant doctor took the sheet of paper and the fountain-pen which were offered him, sat down on the stone, and, with the top of his sombrero for a desk, wrote slowly for ten or fifteen minutes. Then he arose and handed the document, which was signed with his real name, to the detective, who, with one eye on his prisoner, and one on the paper, continued to read the evidence without giving his companion a chance to profit by any relaxation of his vigilance.

“You have told the truth, for once in your life,” was his remark, as he finished reading the paper. “I had found this out myself, fact for fact, all but one or two facts which you give here; but I preferred having your testimony before I brought the matter before the proper parties, therefore I came here after it”—speaking as if a trip to Acapulco were one of the easiest and most commonplace of things.

“You’re d—d cool about it,” remarked the adventurer, eying his adversary with a glance of hate, with which was mingled a forced admiration of a “sharpness” which, had he himself possessed it, he could have used to such advantage. “And now, maybe you’ll be good enough to tell me if the affair kicked up much of a row.”

“I can not talk with you. I want you to lead the way back to our horses, for, since my business with you is finished, I may say that I do not fancy your company. You must go with me before Don Miguel, and we will enlighten him as to your true character, since with him to be ‘forewarned may be fore-armed.’”

“Oh, don’t do that! I beg you to spare me for my wife’s sake—it would kill her, she loves me so much!” and the creature dropped on his knees.

“I would, indeed, rather than blast her innocent heart with such knowledge, allow you still to play your part in that little family—, but I know that, sooner or later, you will contrive to break the heart of that confiding woman, and it might be worse in the future than even now. She has yet no children; she is young, and the wound may heal. It is an unpleasant duty, which I must perform.”