Mycogen is a sector of the planet Trantor, autonomous like most other sectors. It is the third district Hari Seldon and Dors Venabili visited during The Flight. Mycogen is known for its seclusion from the outside and the production of the best microfood in all of Trantor. The social structure of Mycogen is very strict with men being the most important, being referred to as Brothers, and women being very low, restricted to cooking and house duties. Outsiders are referred to as Tribesmen and are looked down upon. Seldon is taken down to the microfood farms where he is given a copy of the Book, the text about the history of Mycogen. He thinks this might give him a clue that he could use in his psychohistory. Through this book, Hari learns of a type of artificial beings known as robots. He thinks that there might be one of these robots in the Elder's Aerie in the Sacratorium, the main temple of Mycogenian culture. He climbs into the Aerie, where he is discovered by the leader of the elders, Sunmaster Fourteen. He is bailed out of this mess by Chetter Hummin.