Second Foundation is the third novel published of the Foundation Series by American writer Isaac Asimov, and the fifth in the in-universe chronology. It was first published in 1953 by Gnome Press.
Second Foundation consists of two previously published novellas originally published in Astounding Magazine (with different titles) between 1948 and 1950, making this the third volume in Asimov's Foundation series. Decades later, Asimov wrote two further sequel novels and two prequels. Later writers have added authorized tales to the series. The Foundation series is often regarded as one of Isaac Asimov's best works, along with his Robot series.
The term also describes the organization by that name which is the focus of the book. The organization's existence (and nothing more) had been revealed in Foundation; it is searched for in Foundation and Empire, and it makes brief appearances in this novel. It would not be described in detail until Foundation's Edge.
Plot summary
Part I: Search By the Mule
Part I is about the Mule's search for the elusive Second Foundation, with the intent of destroying it. The executive council of the Second Foundation is aware of The Mule's intent and, in the words of the First Speaker, allows him to find it—"in a sense". The Mule sends two of his people on a search for the Second Foundation: Han Pritcher, who had once been a captain and a member of the underground opposition prior to being Converted to the Mule's service, and Bail Channis, an "Unconverted" man (one who hasn't been emotionally manipulated by the Mule to join him) who has quickly risen through the ranks and impressed the Mule.
Channis reveals his suspicions about the Second Foundation being located on the planet Tazenda, and takes the ship there. They first land on Rossem, a barren planet controlled by Tazenda, and meet with its governor, who appears ordinary. Once they return to the ship, Pritcher confronts Channis and believes him to have been too successful with the search. The Mule, who had placed a hyper-relay on their ship in order to trace them through hyper-space, appears, and reveals that Channis is a Second Foundationer. Pritcher's emotional bonds to the Mule are broken in the ensuing exchange between Channis and the Mule, and he is made to fall into deep sleep. With only the two of them left, the Mule reveals that he has brought his ships to Tazenda and has already destroyed the planet, and yet senses that Channis's dismay is only pretense. He forces Channis to reveal that Rossem is actually the Second Foundation, and that Tazenda is only a figurehead.
The First Speaker for the Second Foundation appears and reveals to the Mule that his rule is over; neither Tazenda nor Rossem is the Second Foundation, and Channis's knowledge had been falsely implanted to mislead the Mule. Second Foundation agents are headed to Kalgan and the Foundation worlds to undo the Conversions of the Mule, and his fleet is too far away to prevent it. When the Mule experiences a moment of despair, the First Speaker is able to seize control of and change his mind; he will return to Kalgan and live out the rest of his short life as a peaceful despot.
Part II: Search By the Foundation
Part II takes place 60 years after the first part, 55 years after the Mule's death by natural causes. With the Mule gone his former empire falls apart and the Foundation resumes its independence. Because of their enslavement at the hands of the Mule and their wariness of the Second Foundation (who possess similar abilities to the Mule) the Foundation began studying the mental sciences.
A secret cabal is formed within the Foundation to root out the Second Foundation after evidence of the latter's manipulation is found through mental analysis of the former society's key figures. They send one of their own, Homir Munn, to Kalgan to search for clues to the Second Foundation's location. Munn is followed to Kalgan by Arcadia, Dr Darell's daughter.
Since the death of the Mule, the Second Foundation has worked to restore the Seldon Plan into its proper course. In the organization's secret location, the First Speaker discusses the state of the galaxy with a student. The Student is concerned that the Foundation's now tangible knowledge of the Second Foundation's existence would have negative effects upon the former which would then further destabilize the Seldon Plan. The First Speaker reassures the Student that a plan has been put in place by their organization in order to address his very concerns.