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.
At the suggestion of general-store owner Baba Pambazuka, they follow instinctively the intelligent earthworm's habitat in the long-extinct volcano Kukumlima, without a set course. By chance, they stumble upon Kukumlima and discover Gordon Whillikers, a prisoner of the gigantic earthworms (now identified), who is required to annually collect tiny elephant mice for unknown purposes.