Davy and Georgie go ashore after getting a ride down the river from Mike Fink. They hope to trade and get horses from the friendly Chicasaws, but are captured by a hunting party. Back at the camp, Davy meets with the Chief, and is told that the Chicasaws are being blamed for a series of river attacks, and that they are preparing to go to war to defend themselves. Davy asks for some time to clear the Chicasaws and find the real culprits. He and Georgie reunite with Mike and the crew of the Gullywhomper, and they concoct a plan to lure the river pirates out in the open. They disguise the boat and Mike poses as a wealthy banker. In town, they take on a minstrel as passenger, but he is in league with the pirates, and sings songs from the boat to alert his cohorts. The pirates launch a phony Indian attack, and Davy and Georgie pursue the leaders to Cave-In Rock. There, the men fight until a powder keg explodes, trapping the pirates and their ill-gotten gains. The river is safe again, and the Indians are cleared.