There was a mine, way back in the Matto Grosso, said Juan. He thought it might contain silver: there had been the shaft of an old mine there. But now they were deep down in the ground, digging out reddish brown ore, and the cavern smoked and smelled so badly a man could work but an hour or two before being relieved. But the pay was very high. Also, Juan, in his rambling way, spoke of grotesque animals. What were these creatures like? asked Durkin. Then came a shrug, and Juan said they were like nothing else on earth. * * * * * Durkin discounted the part of the story having to do with the strange animals. He thought it was peon superstition. But now he was sure there was a rich mine to be raided. "It's a tough part of the Grosso," he said, turning to Maget. "Sure. Hard to carry enough water and supplies to make it. Say, Juan, who was that big Portuguee with Professor Gurlone? He's blind, ain't he? His eyes were white as milk, and his face tanned black as river mud. Surely is a great big guy, and tough looking, too." Durkin drummed on the table, considering the matter, while Juan spoke of the big Portuguese. The swarthy man with the colorless blind eyes was Espinosa, former owner of the mine. He had sold part of his claim to the Gurlones, but had remained with them as an assistant. Though blind, he knew the depths of the mine and could feel his way about, and direct the peons in their labors. "I've got it," said Durkin, turning back to Juan and Maget. "Juan, it's up to you. You've got to blaze the trail so we can follow you in. And you can steal food and cache it for use on the way, see? We'll come along a day or so after the Gurlones." It took some persuading to make Juan consent to their plot, but the peon yielded at last to money and the promise of part of the spoils. "Maybe you can steal Gurlone's samples and they'll give us a line on what he's up to out there. Whether it's emeralds or diamonds or gold that they're taking out of the mine." Juan was stupid and superstitious, like most of his fellows. He had obeyed orders, digging out the red ore, and that was all he knew. But prompted by the two tramps, he was ready for trouble, too. Juan told them that Professor Gurlone carried a small lead case which he seemed to prize greatly. "Get it, then," ordered Durkin. The two tramps saw Gurlone's party start on the morrow. There were many cases of supplies loaded into launches, some marked Glass, Acids, and so on. Then there were boxes of food and various things needed in a jungle camp. * * * * * Juan, their tool, was working with the other peons, and at ten o'clock in the morning the launches set out, pushing into the current of the Madeira. Old Gurlone, of the livid face, was in charge of one boat, and the gigantic Portuguese, with his colorless eyes and burned complexion, sat beside him.