at this point in the story, the reader has already been told about the hole and the other world. the other world, named in the story only as world 7, is being used by an alien civilization as an experimental ground for transplanting intelligent life from different planets. however, world 7 has inadvertently been infested with a harn, an intelligent predator. the entity overseeing the planet, known in the story only as the warden, needs to eliminate the harn and decides that the easiest way to do this is to open a portal from world 7 to earth. the warden's intention is to have the people of earth kill the harn.