Short stories and essays by Larry Niven. This book includes these pieces:

- "What Can You Say about Chocolate-Covered Manhole Covers?" which is the chilling result of meeting someone who's 'a walking intelligence test.'

- "Bordered in Black" is a story of the dangers of exploration to other worlds.

- "The Fourth Profession" is one of my favourites. A bartender gets talking to an alien... and learns that there is no repeat business when you trade between the stars. The implications are, again, chilling, yet the story is charming.

- "Madness Has Its Place" is a missing tale from Known Space
- "Down in Flames" outlines a story in which Known Space is destroyed
- "Brenda"
- "Building The Mote in God's Eye" is an essay
- "The Return of William Proxmire" a short story featuring Robert A. Heinlein

N-Space goes with Playgrounds of the Mind and Scatterbrain.