Belle Ada has gone to visit Nell and Ethel for a few days at the 8 X 8. The ranchers become concerned when all three girls fail to appear after they had set out in good time to come to the X Bar X to continue their visit there. When the news arrives that some of the rustlers, who had been put away at the end of the first volume, have escaped from the local jail, the hypothesis that the girls had been kidnapped is all but confirmed. The X Bar X boys, with punchers of both ranches, follow the "clews" to locate and liberate the captives, whom they suspect have been detained deep in Thunder Canyon.