Marooned in Realtime is a 1986 murder mystery and time-travel science fiction novel by American writer Vernor Vinge, about a small, time-displaced group of people who may be the only survivors of a technological singularity or alien invasion. It is the sequel to the novel The Peace War (1984) and the novella The Ungoverned (1985). Both novels and the novella were collected in Across Realtime. Marooned in Realtime won the Prometheus Award in 1987 and was also nominated for the Hugo Award for Best Novel that same year.