An Earthman arrives accidentally on a planet where the people are marsupial and changes the lives and fortunes of a family group living there.

With the help of two refugees from a penal colony, three earthmen, separated from a fourth on the planet Torin, elude capture by the Great Elder and gain cooperation for their mission.

Having been absorbed into the traditional life of the Moruia, four Earth people live peacefully on the planet Torin until an unscrupulous diviner tries to seize power.