I appeared at first to attach but little importance to his offer; but as he renewed it whenever the subject was alluded to, I at last employed him. The mine is situated on the margin of a little brook. One day's work of an active man will turn the stream into a fresh channel, and a few inches beneath its bed will be found, mixed with the damp sand and loam, the shells, which, when polished, form the opal. I gave my servant the needful information as to localities and landmarks, and promised him a gratuity of a hundred dollars over and above his wages, in case he succeeded. Having given him instructions, I retained his services until I reached this city, where I determined to await his return, it being more healthy than Vera Cruz. Having selected my lodgings and given him the pass-word by which alone a stranger could obtain admittance to me, with an anxious heart I dispatched him on the mission. ''For three months I had no tidings of him; night and day, I was the prey of doubt and fear. No words can portray the agony of suspense that I endured; the hours seemed days, the days months, and the bitterness of years was crowded into that short interval. At last, thanks be to heaven, my messenger returned.' ''Do you mean Pepito?' I exclaimed. ''The very man,' replied Arthur; 'his journey was successful. You have seen the specimens he brought. I was intoxicated with delight; but Adéle did not share my joy. Nature has given woman a faculty of intuition denied to man. Alas! Adéle's presentiment has been verified; your account of the interview between Pepito and his friend proves her fears were well-grounded.' ''In what way?' ''In _this_ way; it shows we have an enemy who has an inkling of our secret, and is striving to snatch the prize from us. What course to take I am at a loss to know. Adéle advises to make sure of Pepito, at any price.' ''And that strikes me as being your surest if not your only course.' ''Yes, the surest; but how to make _sure_ of him?' ''By outbidding your competitors, and proving to him that in adhering to you he is best serving his own interests.' ''But he is base enough to take bribes from both sides, and betray each.' ''Oh! that I were a man!' exclaimed Adéle, 'this fellow is the only one who knows our secret. One man ought not to stand in fear of another. Only _one_ man crosses your path, Arthur.' ''Unless I murder him, how can he be silenced?' ''_Murder_ him! It is not murder to kill a robber. Were _I_ a man, I would not hesitate how to act.' ''The anxiety of Pedro,' I said, 'indicates you have an enemy. Have you any idea who he is?' ''I believe,' said Adéle, 'that I know him.' ''Are you sure there is only one?' ''Why do you ask?' said the woman, fixing her eye upon me as though she would, in spite of every obstacle, read my inmost thoughts. ''Because I fancy there are _two_, for instance, Brown and Hunt.' 'At the mention of these names Adéle started to her feet, exclaiming: