"At the Core" is an English language science fiction short story written in 1966 by Larry Niven. It is the second in the series of Known Space stories featuring crashlander Beowulf Shaeffer. The short story was originally published in Worlds of If, November 1966, and reprinted in Neutron Star (1968), and Crashlander (1994).The novel Fleet of Worlds is set in the aftermath of the story, from the Puppeteer point of view.