Deck looked at Artie, and Artie looked at Deck. A significant smile passed between them, but they said nothing. As soon as they had finished their supper they followed the planter into his library, which had been lighted before. It was an important conference which followed there, and it must be left in progress in order to return to the boat in which the boys were pursuing their adventure on the creek. Artie had the floor on the boat, and he had just recalled the time when Noah had spoken to him about being out so late the night before. Deck remembered it very well, and also that his cousin had evaded an adequate explanation of his absence from the house when he ought to have been in bed. "You never explained why you were out so late that night," said he. "I wanted to look into the matter a little more before I said anything, for I didn't care to make a fool of myself," replied Artie. "You have a habit of keeping your mouth shut pretty tight," said Deck with a smile. "I don't believe in talking too much about things you don't understand, and I meant to have looked into the matter before this time, but somehow I haven't had the chance to do so," replied Artie, still pulling his oar. "I'm going to tell you about my night adventure now, and you can judge for yourself whether we are going on a wild-goose chase up the creek." "All right; and I will keep my oar moving all the time, so that we shall be getting ahead while I listen," replied Deck. "I was in the canoe, and I had gone farther up the creek than I had ever been before," Artie began. "You have been up the road that leads to Dripping Spring and the Mammouth Cave. It crosses the railroad about five miles before you get to the spring, and the creek flows within a quarter of a mile of this place." "I remember the place very well; for Levi stopped his team there to let the girls get out and pick some flowers. I could see the creek from this spot," added Deck. "Then you know the place. I had been up the creek three or four miles farther, and I was on my way home. I had been ashore just abreast of Dripping Spring, and I got interested in looking over a sink,--I believe that is what they call these holes in the ground down here,--and the sun went down before I thought how late it was getting. But I found the hole led into a cave; but it was too dark for me to explore it. I made a note of it, to bring a lantern up and survey the cavern when I had plenty of time to do so." "That will be a good job for both of us some time," suggested Deck. "I couldn't tell how far I was from home, but I knew it was a long distance, and I made tracks for the canoe as soon as I saw that it was getting dark. I hurried up till my arms ached so that I had to stop and rest. I made up my mind that I must take it moderately or I never should get home.