Redshirts by John Scalzi

In this satirical science fiction novel, the story follows the adventures of a group of ensigns aboard the Universal Union's flagship Intrepid. They quickly realize that their ship's officers are frequently embroiled in dramatic and dangerous missions, while the lower-ranked crew members—often clad in red shirts—have a startlingly high mortality rate. The ensigns come to the shocking conclusion that they are actually characters in a badly written television show, and they must navigate a metafictional quest to confront their creators and change their fates to avoid being expendable casualties in the next away mission. The novel plays with the tropes of classic space operas and the concept of narrative determinism, delivering both humor and existential inquiry into the nature of free will and destiny. The 10015th greatest book of all time