Embassytown is my second Mieville work (I found The City and The City interesting, enjoyable, and yet somewhat lacking). The novel seemed to spend a long time getting anywhere, and it was a bit hard to get into, the way that it got there, but in the end the payoff was worth it. This is probably more like 4.5 stars than 4--the slow build-up wasn't bad, per se, I just wish there could have been a more engaging way to pull us in deeper faster. 
 Our narrator, Avice Benner Cho, is a native of Embassytown, the human outpost on the alien world Arieka. She grew up there, got away from this fascinating backwater because she had the ability to immerse, to maintain consciousness while traveling through the Immer, which is the humans' method for faster-than-light travel across the universe. After she marries a linguist, however, she is drawn back to Embassytown by his desire to study the language of the Arieka Hosts, a desire to avoid the politics of her Immerser profession, and the subtle call of home. 
 The language of the Arieki is central to the novel. These aliens have a language that is unique in two ways: because they have two mouths, they speak a double language, a language which only makes sense with two voices; also, for them, language (or Language, since they can only conceive of one) is purely representative of reality, meaning--among other things--that they cannot lie. They also cannot learn other languages, or even really understand that other languages exist. Sometime in the past, through a fortuitous discovery, it was found that the only way humans could communicate with the Hosts was to have two speakers who were empathically linked in some way--from twins, they moved to clones, with special training to allow them to work as one. These doubled individuals are the Ambassadors, the only humans who can speak to the Hosts (or even be understood as speaking). 
 I don't want to get too far into the plot, but suffice it to say that intergalactic and local politics lead to a crisis of world-shattering proportions, which Avice and her allies must solve through a deeper understanding of these alien beings--as well as a greater understanding of human beings. 
 One of the sub-genres of science fiction is of the alien anthropology variety, hinging on the unique characteristics of an alien species that are understood dimly at best by the characters and the reader when the novel starts. It's a sort of puzzle or detective story, and in this case the aliens--however much their forms are strange to us--are ultimately at their strangest when it comes to the seemingly-simple difference of being incapable of lying, and the linguistic and consciousness differences that follow from that difference. In the process, Mieville offers an interesting exploration of what being human means, which in this case means beings who use language the way we do. 
 I listened to this novel as an audiobook, and I wanted to comment on the production as well. Susan Duerden, narrating, is Avice. The POV is 1st person narration, and she carries it off perfectly. I don't know how this was handled in the text version, but Language is represented here by two voices overlaid, as they are described to be, and it works nicely.