Nayler’s sci-fi debut, The Mountain in the Sea (MCD, Oct.), hinges on the discovery of intelligent octopus life.

Why did you decide to set the story in Vietnam’s Con Dao archipelago?

I was the Environment Science Technology and Health officer at the consulate in Ho Chi Minh city from 2011 to 2013, where I did a lot of programs on the environment. There was one where we brought U.S. scientists in to work with youth in the Con Dao archipelago. They taught youth how to document and photograph biodiversity, report poaching, and better protect wildlife. So I spent quite a bit of time working there and I also went to the archipelago several times just to explore on my own. I knew the islands so well that while I was writing, I could sort of turn my head and see everywhere the book was taking place.

How did you conceive of the octopuses’ language?

I presented myself with a problem: I wanted to write a book that was about believable interspecies communication because I felt that I had not seen first encounter stories that fully explained the linguistic mechanism of the other being. I thought very, very hard about the scientific concept of exaptation, which is how we take one structure in the body and use it for something it wasn’t intended for at first. A very simple example is how human beings use their breathing and eating apparatus to speak. It wasn’t designed initially for speech, but we’ve come to use it that way. So I thought about what an octopus would use to communicate. They can do a lot with their form that we can’t; they can do a lot with their skin and the passing cloud, a hunting mechanism that octopuses use where they imitate a shadow crossing their skin to startle prey. So I came up with this idea that the octopus, if it evolved symbolic communication, would use the passing cloud as the tool to base its communication on, and it would display its language on its skin. From there I thought about what would the base symbols be that it might pull from its environment, and I started to construct the language.

A fascinating relationship develops between Ha, the scientist studying these octopuses, and Evrim, her android assistant. Tell me about that.

For me, the relationship between Ha and Evrim, along with Evrim’s internal identity struggles, is about what it means to be not considered human, what it means to be not considered conscious, and what it means to be an outsider. The relationship really emerges out of this sense of being outside. Ha has a sense of herself as an outsider in the same way that Evrim has a sense of theirself as an outsider. The dialogue that recurs between them about personhood is one of the ways that I tried to get at how we bridge communication gaps between unlike perspectives, which is one of the core themes of the book: trying to understand the octopuses, but also trying to understand Evrim, and trying to understand one another.