In particular, the administrative planet, honeycombed and tunneled with offices and staff, is vulnerable to attack or breakdown. The only person willing to confront this imminent catastrophe is Hari Seldon, a psychohistorian and mathematician. Seldon can scientifically predict the future, and it doesn't look pretty: a new Dark Age is scheduled to send humanity into barbarism in 500 years. He concocts a scheme to save the knowledge of the race in an Encyclopedia Galactica.