Father Ramon Ruiz-Sanchez S.J., is a part of a four man scientificcommission to the planet Lithia, there to study a harmonious society ofaliens living on a planets which is a biologist's paradise. He soon findshimself troubled: how can these perfect beings, living in an apparentEden, have no conception of sin or God? If such a sinless Eden has beencreated apart from God, then who is responsible?