At the advice of general-store owner Baba Pambazuka, they pursue intuitively the intelligent earthworm's habitat in the extinct volcano Kukumlima, without set directions. Finding Kukumlima accidentally, they discover Gordon Whillikers a prisoner of the earthworms (now identified with gigantic size), required to annually collect the tiny elephant mice used by the worms to purposes unknown.
Guided by general-store owner Baba Pambazuka's advice, they embark on an intuitive search for the intelligent earthworm's habitat in the long-dead volcano Kukumlima. In doing so, they happen upon Kukumlima and encounter Gordon Whillikers, a captive of enormous earthworms (now recognized), who is tasked with collecting tiny elephant mice every year for reasons unknown.