I am moved to write by one story in particular "PRoblem", by Alan Nourse, which I read recently. It's truly aggravating because it starts out as a fun illustration of the many, many possibilities for human/space-alien conflict that don't involve hostility. I was thinking "This is really good for 1956!" And eventually I thought "Wait, they're resolving the really good conflict with a few pages to go, could it be that..." Oh no! In a shocking twist, the aliens were out to screw us over! So I got caught by the twist, but at what cost? I was caught because the story convinced me it was too good for a cheesy twist ending.
I guess since it's in the public domain now I could just write my own ending. That won't solve the general problem though.
(6) Wed Jan 16 2008 16:59:
My least favorite science fiction story type is "space aliens act friendly but in a shocking twist they're out to screw us over." You no longer see this much in published stories, but I encounter it with some frequency because I'm still catching up and because I often take a lucky dip (love that phrase) into the old stories published at Project Gutenberg.