David C commented on Station Eternity by Mur Lafferty (The Midsolar Murders, #1)
This is a really fun book. Like "Six wakes" this is an outside of the usual box take on a mystery novel. Six Wakes has a subtext (the ethics of human cloning) that made it a Hugo contender.
Station Eternity may have less going on thematically, but it is zanier, and a lot of fun to read.