I am pleased to report the republication (in e-book format) of the young adult sci-fi novels of Helen M. Hoover. Nearly all of her books had been out of print for 30 or 40 years, and if I am typical of my generation they left a lasting impression on thousands of readers.
Hoover was by no means a perfect writer. Plot was not her strong suit, or more precisely she didn't seem that interested in it. Her stories moved forward at a rather languid pace, even when the characters were in the midst of a rescue operation or a war. This gave her time to describe settings, which she did quite well - misty marshes at dawn, dense forests, decaying mansions, smoky wooden lodges - along with the vividly imagined animals (creeping molluscs, wild pigs, bewildered alien birds) that inhabited them. Her characters also tended toward flatness and disposability, though she usually included a few exceptions, like the cunning and brutal Major in Children of Morrow and the world-weary grandfather in The Shepherd Moon. This particular flaw she shared with most SF writers. Like them, Hoover primarily wanted her books to explore ideas, ideas that would challenge readers' expectations and leave them unsettled.
Her earliest novels, Children of Morrow and Treasures of Morrow (1973/1976), featured a conflict between two post-apocalyptic societies, one ("the Base") superstitious and patriarchal, the other (the Morrow community, "Lifespan") high-tech, egalitarian, and psychically sensitive. Children presented readers with a straightforward rescue mission and a clear set of heroes and villains, but its sequel blurred the line between the two somewhat, as a follow-up Morrow expedition to the Base trashes the impoverished inhabitants' sacred shrine and threatens their survival. Hoover more clearly challenged the "technological/sensitive/good versus primitive/brutish/bad" dichotomy in her later novels. The Delikon (1977), which takes place after a successful alien invasion of Earth, describes the humans' subsequent overthrow of their alien masters from the standpoint a Delikon, a genetically modified alien who is trying to teach human children the ethics of her people. Hoover makes clear that neither side has a monopoly of virtue or villainy; the Delikon value beauty and harmony but have imposed their will by force, the humans are grubby philistines but are also seeking genuine freedom. Another Heaven, Another Earth (1981) inverts the central tropes of Hoover's early novels even more thoroughly. The inhabitants of the lost colony of Xilin are tall, graceful, fond of natural beauty and fulfilling work; their high-tech rescuers from Earth are overbearing and aesthetically crude, interested primarily in profit and glory.* The Shepherd Moon (1984) brings together two societies that are both fundamentally flawed, predicated on artificial scarcity, abuse of children, and indifference to suffering - and tells their story through an antagonist who liked the status quo and a protagonist who has no idea how to change it. Like the best young-adult writers, Hoover is unafraid to pose questions and conundrums that make the most sanguine adults uncomfortable.
* The novel does make it clear, however, that the Elf-like colonists' lives are unsustainable: the alien environment is slowly poisoning them, shortening their lives and curtailing their fertility.