"Babel-17" by Samuel R. Delany

Set in a far future where humanity is engaged in an interstellar war against "invaders", the novel opens as an alliance military general engages the services of ex-intelligence officer-turned-poet, Rydra Wong, to assist in deciphering an enemy code, referred to as "babel-17", which has been associated with several instances of enemy sabotage. Rydra discovers that the code is in fact a language, unlike anything seen before and from partially deciphering intercepted transmissions, determines the location of the next planned attack. After requisitioning a starship to travel to the next target, Rydra assembles a crew composed of a part-human-part-animal pilot, a menage-a-trois team of navigators, discorporate ghosts, a slug and a ragtag platoon of first-time travellers. Rydra continues to decode the mysterious language and after the assassination of a high-ranking alliance weapons-developer (by his own genetically-engineered spy-bot), the crew of Rydra's ship experience an increasingly dangerous series of acts of sabotage to their own ship, which can only be attributed to somebody in the crew. After one of these acts, the crew is knocked unconscious and the ship set adrift. The crew are rescued when discovered by a band of roaming mercenaries, amongst which Rydra meets "Butcher", a mysterious figure who does not understand the concept of "I", similarly to the lack of the same concept in the language Rydra continues to decode. Eventually, with the help of her crew, Rydra discovers that the language itself is the element of sabotage developed by the enemy; by learning to speak and think babel-17, the structure of the language causes it's interpreter to participate in self-destructive behaviour, and that Rydra was responsible for the acts of sabotage to her ship.

The novel explores the concept of linguistic relativity, that is that the structure of a language affects the way in which the speaker thinks and constructs their world view. The novel considers an extreme form of linguistic relativity which was considered a plausible theory of psychology when the book was written in the 1960s but is now considered less plausible. This was a really interesting aspect of the book; Delany does a good job of exploring this concept without being too heavy-handed and getting in the way of the story.

"Babel-17" is a strange book, and I didn't quite know how to take it. Delany paints a colourful backdrop to the story including discorporate ghost worlds, progressive three person sexual relationships and alternative underground cultures including body manipulation. A lot of this was really interesting but also a lot of it didn't quite hit the mark of plausibility for me (i.e. pregnant women chosen as pilots because they have fast reflexes? .. I'm not so sure). This flavour of bizarre world wasn't exactly my cup of tea (I much prefer the strangeness of authors such as Philip K. Dick), however I think there are a lot of readers out there who would like it, so I would recommend adding it to your list, also because it's short and well-paced.