"Later Than You Think" by Fritz Leiber is a science fiction short story written in the early 1950s. The narrative explores themes of intelligence, extinction, and the nature of civilization through the interaction between an Explorer and an Archeologist who examines the remains of a previously unknown intelligent species that once inhabited Earth. The story contemplates the significance of their existence and the inevitability of cultural and species decline. In the story, the Explorer returns from an interstellar journey, disillusioned after failing to find intelligent life in space. Intrigued by the Archeologist's recent discovery of artifacts from an ancient, intelligent species, he becomes eager to learn more about them. The Archeologist describes the species as somewhat similar to humanity, highlighting their cultural achievements, technological advances, and eventual decline, potentially due to their inability to manage their emotions and aspirations. Throughout their conversation, the Explorer grapples with a sense of melancholy understanding as he recognizes the parallels between the lost species and humanity itself, culminating in a reflection on the impermanence of all civilizations. The story ends on a poignant note, emphasizing the shared fate of intelligent beings and the remnants they leave behind. (This is an automatically generated summary.)