1981’s The Guardian of Isis is the second volume in Monica Hughes’ Isis trilogy.
Fifty-five years after Pegasus II delivered eighty-odd colonists to Isis, sole habitable world of the star Ra, the human numbers have swelled to about eight hundred. Only a few of the original colonists are still alive. David London is one of those few. When his father died, David grabbed the office of president for himself. He has never stepped down. David has spent his long decades in power enforcing his vision of the perfect community: advanced technology forbidden, strict taboos imposed, women reduced to the status of domestic animals. Above all: no exploration of the world outside their small valley.
Jody n’Komo, one of those eight hundred colonists, is the grandson of one of David’s bitter (vanquished) rivals; he has the misfortune to look like his grandfather. David has transferred all the hate he felt for the grandfather to the grandson. Sooner or later, he will find some crime for which to punish young Jody.