1977’s The Rains of Eridan is a standalone young-adult hard SF novel by H. M. Hoover.
The Aurora Corporation thought the life-bearing world Eridan promising enough that it funded three bases:
Base One, the administration and living colony research centre;
Base Two, the agricultural research base;
Base Three, the science base.
The bases are separated by hundreds of kilometres, far enough that even if one base were to fall to calamity, the other two would be spared. It seems that the spread was not great enough; bizarre collective madness has attacked all three bases.
Theodora “Theo” Leslie, who has spent the last month out in the field gathering data on the Eridan lifeforms, has no idea how bad matters have become. Not until she witnesses a double murder.
Base One’s madness (irrational paranoia) bloomed into open mutiny. Simon and Elizabeth Orlov paid the price, led out into the wastelands before being gunned down. But there were three Orlovs targeted for summary execution. The third, young Karen Orlov, is very much alive. Simon and Elizabeth are past help, but Theo can aid Karen. Which she does.
The pair’s immediate challenges are twofold: avoid any Base One patrols (lest Karen and Theo be murdered as well) and survive outside the base. The region’s dry season is coming to an end; the rainy season will be challenging. But Theo should be able to manage the second challenge: she has already been doing quite well at surviving on her own.
As they cross the hinterland, Theo and Karen find time for field observations. Not only is the data potentially useful, but it gives Karen a distraction from her recent loss. Perhaps unsurprisingly for the child of scientists, Karen has a keen eye. A chance discovery in a cave seems likely to earn her the only immortality that matters1.
Base Three’s Commander Jonathan Tairas crosses paths with Theo and Karen, The two hikers take advantage of Jonathan’s offer of a ride to Base Three. They arrive to find Base Three deserted. Half of the personnel have marched off into the wilderness, lured by rumours of valuable gems to be found. The other humans have simply vanished.
What is causing the manias plaguing the bases? Where did the missing Base Three staff go? Are the events connected? All mysteries Theo will have to solve before tackling the most difficult question of all: what is to become of orphaned Karen, now light years from any blood relatives?
I thought for a long time I’d managed to overlook Hoover in the 1970s. As soon as I saw the Charles Mikolaycak cover for the 1977 Viking Press edition, I realized I had read at least one of her books, but forgotten it.
I often mock old-time covers, but in this case, The Rains of Eridan has been well served by its covers. The Mikolaycak cover seems most evocative, but the 1979 Sharon Vintson and the 1979 Mike Heslop covers both hint at important elements of the plot, while pleasing the eye. Even the recent ebook cover (unknown artist) is attractive albeit uninformative.
Given that this is a completely new world, the researchers seem remarkably blasé about exposing themselves to its unfiltered air. Presumably this is because every other human-colonized world has lacked aggressive airborne infestations or even toxic allergens. That (or the fact most humans appear to spend their lives in star ships and orbital colonies) has blinded them to the possible hazards of natural worlds.
Even though the book starts with a double murder followed by a desperate cross-country march and the discovery of a massacre2, it is nonetheless charming and engaging in its own way. The characters, and their relationship, are appealing. Theo, who had never considered taking a young protege in hand, finds herself working with Karen, who desperately needs a sympathetic adult. I cared what happened to them. Hoover manages to deliver both a decent puzzle plot and an engaging emotional drama.
1: Scholarly immortality as a citation in a footnote. More than most of us get.
2: The horror of the massacre is presumably compounded (offstage) by the anguish of those who committed it while mad and are now sane.