An early 70s last night of the world story that ends up as an apocalyptic story looking forward to the post-apocalypse. Niven rigorously explores the various explanations and possibilities.
The suspense (which of the above categories will we finish in?) is very well maintained. By the end, I really wanted the main characters to survive to confront the challenges of a post-apoc world.
My mother in law does not usually like science fiction, but she identified with the main female character in this story whose last night of the world wish was to go and window shop at the jewellery stores along Rodeo Drive.