Foundation's Edge (1982) is a science fiction novel by Isaac Asimov, the fourth book in the Foundation Series. It was written more than thirty years after the stories of the original Foundation trilogy, due to years of pressure by fans and editors on Asimov to write another, and, according to Asimov himself, the amount of the payment offered by the publisher. It was his first novel to ever land on The New York Times best-seller list, after 262 books and 44 years of writing. Foundation's Edge won the Hugo Award for Best Novel in 1983, and was nominated for the Nebula Award for Best Novel in 1982. Believing the Second Foundation still exists (despite the common belief that it has been extinguished), Golan Trevize is sent by the current Mayor of the Foundation, Harla Branno, to uncover the group while accompanied by a scholar named Janov Pelorat. The reason for their belief is the Seldon Plan appears to be proceeding fully on course, despite all the disruptions caused by the Mule. They attribute this fact to unknown interventions by the Second Foundation. After sharing a few conversations with each other, Trevize comes to believe the Second Foundation lies on a planet in which Pelorat is an expert-the mythical planet of Earth. No such planet exists in any database, yet several myths and legends all refer to it, and it is Trevize's idea that the planet is deliberately being kept hidden. Meanwhile, Stor Gendibal, a prominent member of the Second Foundation, discovers a simple local-who lives on the same planet as the Second Foundation-has had a minor alteration made to her mind. This alteration is far more delicate than anything the Second Foundation can do and, as a result, he determines a greater force of Mentalics is operating in the Galaxy-a force as powerful as the Mule himself. Having shown interest in Trevize earlier (as he is an individual who has spoken out against the Second Foundation frequently), Gendibal endeavors to follow Trevize, reasoning that he should be able to find out who has altered the mind of the native. Using the few scraps of reliable information within the various myths, Trevize and Pelorat discover a planet called Gaia, which is inhabited solely by Mentalics, to such an extent that every organism and inanimate object on the planet shares a common mind. Having followed Trevize by their own means, Branno and Gendibal reach Gaia at the same time. Meanwhile, Trevize is made to decide between three alternatives for the future of the human race: the First Foundation's mastery of the physical world and its traditional political organization (i.e., empire), the Second Foundation's mentalics (and probable rule by mind control), or Gaia's absorption of the entire Galaxy into one shared, harmonious intellect. After Trevize makes his decision, the intellect of Gaia adjusts Branno's mind so that she believes she has successfully negotiated a treaty tying Sayshell to the Foundation (and that Gaia is just a Sayshellian myth); Gendibal is sent back to the Second Foundation under the impression that the Second Foundation is victorious and should continue as normal. Trevize remains uncertain as to why he has chosen Gaia as the correct outcome for the future.