This is the first book in a series of three. Here the book Description:
Olwen Pendennis is the Keeper of the Isis Light. She and her companion, Guardian, have lived alone on the planet Isis since the death of her parents. But then a group of colonists arrives on Isis from Earth, settling in the valleys � the only places where they can breathe and not be harmed by the planet�s harsh sun. Olwen fears these new inhabitants may ruin her world forever, and at first, it appears she is right.
