Second Foundation by Isaac Asimov

This collection of excerpts details the covert operations and eventual reveal of the Second Foundation's location and methods, a group of mental scientists dedicated to guiding the galaxy according to Hari Seldon's Plan. Initially, characters like The Mule and General Pritcher struggle to locate this elusive Foundation, believing it to be at the "other end of the Galaxy." However, through a complex scheme involving an unconverted agent named Bail Channis and later a carefully manipulated group from the First Foundation, the true location is unveiled to be Terminus itself, the seat of the First Foundation. The narrative highlights the Second Foundation's use of subtle mental influence and misdirection to manipulate events, including the war with Kalgan and the actions of key individuals like Arcadia Darell, ensuring the Seldon Plan remains on track despite unforeseen variables like The Mule. Ultimately, it is revealed that the location "Star's End" referred not to the galactic periphery, but poetically to Trantor, the former Imperial capital.