Failure did not daunt Leighton. He was convinced that by persevering in their exploration they would solve the mystery of the cave, gain tidings of David, and run down Raoul. Una shared his optimistic view, and both chafed at the reluctance of their companions to go ahead with the energy their plight demanded. The fact is, the feeling that they were caught in a cavern of unknown extent, connected with certain mysterious happenings in the immediate past, mixed up in the legendary history of a vanished race, and inhabited even now by strange beings in outlandish costumes, had a blighting effect upon them. Mrs. Quayle refused to be comforted and, as it was out of the question to go on without her, Leighton, like an astute general, proposed having lunch before doing anything else. Every one brightened up at the idea; it was one of those masterstrokes of policy that, when all else fails, saves the day. Miranda declared emphatically that food was "good for the estomach," and, as no one thought otherwise, they fell to with an appetite sharpened by their exertions and made fairly razor-like--although this they did not realize--by the bracing atmosphere of the cave. There were bollos of corn and yucca--yellow, white, brown--variously flavored, soggy, solid. This was a concentrated food that just hit the need of a party of marooned picknickers. And there were large flat disks of cassava, a native bread that Mrs. Quayle declared, with some reason, resembled chips of wood, more than anything else, in taste and toughness. This, too, furnished the maximum of nourishment in a small space. These foods, with such fruits as the almond-like sapoti, the juicy nispera, the delicate chirimoyo, furnished a meal that aroused Miranda's enthusiasm, although to the untrained New England palate it was not quite so satisfying as it might be. The thought, too, that after this supply of food was exhausted, there would be nothing to eat, and no way of getting anything to eat, spoiled just that part of the picnic that should be most enjoyable. And then, worse than all, unthought of until now, there was the appalling problem of--water. In the lunch bags of Doctor Miranda and General Herran there were two small bottles of red wine; but when this was offered to Mrs. Quayle that unhappy lady's thirst for water reached an acute stage. She declared that all wine was poison, and that she would die if she couldn't get a drink of water. Even Leighton was disturbed. Water they must have, but--did it exist in a cave that was, apparently, caused by fire and not--as all respectable caves are--by water? "Guatavita!" exclaimed Miranda, smacking his lips after a deep draught of claret. "Guatavita!" echoed Leighton irritably. "Why not say the river Magdalena? How are we to reach Guatavita?" "It is near," was the complacent reply. "It come into the cave." "How do you know that?" "Always there is water in the cave. And here--there is the lake outside."