It had been settled among the boys at the start that under no conditions were they at any time to leave their passenger alone aboard the houseboat; and Jerry even insisted that as much as possible, someone be in the cabin when he was. For, of course, Jerry still believed that there must be a wonderful treasure aboard the _Pot Luck_, hidden under some loose board, or in a cranny that as yet he had not been able to find, though he would never give up looking. And when the boy was amusing himself in sounding the walls, and dipping into all the little nooks he could find, Frank saw that the old man’s eyes would follow him, as though he might be secretly amused. But never once did Luther Snow ask the reason of this search on Jerry’s part. Perhaps he understood, from various allusions passing between the boys, that Jerry was in search of a secret hiding place; but as it was none of his business he had the good sense to keep still. They were now drawing close to Cairo, situated at the junction of the Ohio with the Mississippi. And their stock of provisions being rather low, the houseboat was tied up at the lower end of the city, while Frank and Bluff went ashore to make purchases, and have them sent down. Having done this duty, and been assured that the stuff would be delivered at once, the boys went on to the post office, and to do several other little errands. Thus they arrived in the vicinity of the place where the boat had been left several hours before, and with evening only a short time off. “What does all that yelling mean, do you suppose, Frank?” Bluff asked, stopping to listen. “Well, we heard that the roustabouts and stevedores were on a strike here, you remember,” his companion replied; “and so, perhaps they’re having a little fun with some of the strike-breakers, who, they say, have been brought across from Missouri to take their places.” “Whew! that means a fight, with stones flying, and some broken heads,” Bluff remarked. “I’ve always wanted to see what a riot looked like.” “You come right along with me,” observed Frank, as he hooked his arm in that of his impulsive chum. “It’s not our funeral, yet; but it might be, if you thought to stand around when a riot is going on. Here they come now, and we’ll have to run for the boat yet. They seem to be chasing some men, too!” “Say, Frank, look at that boy running with the crowd!” cried Bluff, excitedly. “There, he’s down now, and I guess a stone must have hit him, No, he’s on his feet again, and making this way as fast as he can sprint, with the mob howling after him. Doesn’t he remind you of Ossie Fredericks; but, of course, it couldn’t be him! Yes, as sure as I’m talking, I do believe it is; and he’s going to get his medicine from that crazy crowd of longshoremen, if something don’t happen to save him!” CHAPTER XVII—THE FUGITIVES OF THE LEVEE Frank seldom acted from impulse. Still, he had a habit of thinking quickly in an emergency, and seldom wasted time.