Drew was somewhat puzzled at this bit of feminine psychology, but he gathered some comfort from it, and this was perhaps after all the result that Ruth was seeking. "Do you notice, Allen, how fresh the air seems to be in here?" she asked. "I've been wondering at that," he answered. "To tell the truth my worst fear has been that it would get too close and foul for us to breathe. But it seems to be just as sweet now as it was at the beginning." "What do you suppose is the reason?" "It must be that the cave is a little larger than it seems to be. It seemed to be getting bigger and bigger as I went further into it. If that is so, it accounts for the fact that the air supply has not yet begun to be vitiated." "But mayn't there be any other reason?" she asked. "I can't think of any other," he answered. Then as a thought suddenly struck him, he jumped as though he had been shot. "Why didn't I think of that before?" he fairly shouted. "There may be another entrance!" CHAPTER XXIV THE ALARM Unaware of the possible tragedy that was being developed within a few hundred yards of them, Tyke and Captain Hamilton had kept on digging in the excavation. For Tyke had refused to be kept out of the work of recovering the treasure, and when Drew had strolled off with the intention of discovering what had frightened Ruth and had been followed shortly after by the latter, the old man had seized Drew's abandoned shovel and had gone lustily to work. "Too much of a strain on that game leg of yours to be heaving up those shovelfuls," the captain protested. "Nary a bit of it," answered Tyke. "I ain't ready to be put on the shelf yet, not by a blamed sight, and I guess if it came to a showdown, Rufe, my muscles are as good as yours." "You're a tough old knot all right," admitted Captain Hamilton, his eyes twinkling. "But there's no sense in your doing Allen's work. Where in thunder has the boy gone anyway?" "Oh, he'll turn up in a minute or two," returned Tyke. "Wherever he is you can bet your boots he's doing something connected with this here work of treasure seeking. It simply ain't in that boy to lay down on any job." "Drew makes a hit with you all right," laughed the captain. "And why shouldn't he?" asked Tyke belligerently. "He's been with me for some years now, and I've had plenty of chances of sizin' him up. If there was a yellow streak in him, I'd have found it out long ago. If I'd had a son of my own, I wouldn't have asked for him to be any better fellow than Allen is, and nobody could say any more'n that. He's got grit an' brains an' gumption, an' more'n that he's as straight as a string." "Go ahead," laughed the captain, as Tyke paused for want of breath. "Don't let me stop you."