The experiment arose from my instinct that what’s most exciting about other people, what’s most likely to inspire our passion and our empathy, is their mystery; when we cease to acknowledge that mystery and convince ourselves that we truly know them, rejecting the possibility that they might not be quite the people we imagine, is when we stop perceiving them as enigmatic other human beings and only as a type of themselves.

When I have my SF hat on, I try to rein in the more fantastic elements so I can at least pretend to a veneer of scientific respectability. The idea that one response to a more sea-bound world would be to engineer a human subspecies that could make use of all that coastal land we’re likely to lose seemed just on this side of plausible (especially if the attempt, as per the story, is not exactly government-sanctioned).

I’m a great believer in Real Fantasy. If I’m expecting a reader to follow me into the dark woods of folklore, dream, and metaphor, I figure I’d better leave them a trail of good, hard, palpable pebbles to follow, and maybe some interesting smells, a beckoning sound or two, and some nice gingerbread to eat on the way (with details adjusted for regional variation).

I wrote this as a birthday present for China Miéville, and as it was a gift, I put bunch of his favorite things into the story—revolution, cephalopods, etc. If we’re talking sparks, this story is kind of in conversation with China’s brain. His brain lights mine up daily. Some of the best things I’ve ever written have come from discussions we’ve had. He challenges me to work in forms I hadn’t thought of working in, and to use things I’d thought were too difficult to use.