Though the sixteen-year-old Hohu twins are older than Dorothy and Frank Warren and their friend Pug, they eagerly look forward to showing their friends from Philadelphia their native island of Hawaii. Kam Hohu is particularly anxious to show the mainlanders the volcanic areas of the island, and though they are trapped within a crater, imprisoned by three whimsical Japanese soldiers who, ten years after the armistice, believe that the war is still on, and nearly obliterated by the furious eruptions of Mauna Loa, the five children not only thoroughly relish their ordeal, but help to vindicate a Chinese ranch hand who has been unjustly accused of cattle stealing. There is humor, adventure and interesting geographic detail in this lively tour of the Hawaiian Islands.