Tideline, by Elizabeth Bear

I have been rapidly making my way through '21st Century Science Fiction', and find it delightful. It is an interesting exercise to ask yourself why these stories could only have been written today, and not fifty years ago. There is no one answer to that question, but there is no doubt that all of the writers take their science fiction and its metaphors very very seriously: their style and tone indicate a fearless and respectful internalization of the conventions of science fiction which, in malicious hands, can be made out to be twee and at best, charming. There is, indeed, a lot of charm in all of these stories, but only the best kind of charm, that comes of not having to apologize for what you're doing to the world. 'Tideline' encapsulates all of these qualities, and is a magnificent exercise in brevity and restraint.