Mai is a colonist on Shanti, entranced with this alien world and its permanent spring. Although it took ten years to travel to the planet from Earth, to her it feels like only a few weeks. And now she has so many letters to catch up on. Her mother wrote her every week.
How can she tell her mother what has happened to her, that she has been infected with an alien parasite. That soon she will no longer be Mai at all, not really.
I’ve been infected by a parasite. I won’t tell you what because I don’t want you to search for it. By the time this reaches you it won’t matter much, anyway. In fact, I’m forbidding you right now from looking for anything or asking anyone. Apparently I have about twelve hours as myself. They won’t say what happens next, because it’s kind of unpredictable. There are lots of animals who’ve had it, but only two people. They won’t tell me.
On one level this story makes you never want to touch nature again. It is like learning for the first time about how toxoplasma makes the rats it infects love cats and gives them suicidal tendencies. Parasites that take control of their hosts and change their behaviours are just plain creepy and squicky and real.
But just as Mira Grant’s Parasitology series is about much more than just body horror this short story is also about what makes us people. Is it our memories, our emotions? And how do we know why we are doing the things that we are doing?
And if that sort of story strikes your fancy there are plenty more recommendations on the Metafilter thread where this first came to my notice.