Forward the Foundation is Asimov's sequel to the prequel for his Foundation series. Commencing immediately after Prelude to Foundation where Hari Seldon developed the concept of pyscohistory and then spent his time trying to figure out a way to reduce the concept to practice while staying alive and avoiding everything interested in either getting their hands on psychohisory or trying to kill him, this tale follows Hari throughout his life as he works out the details of the mathematics, while at the same time enjoying a potpourri of odd jobs, including First Minister of the empire. All the setups for the actual Foundation stories are outlined including robots from the pre-Trantorian era, the need for two Foundations, and the origins of the mental evolution for the 2nd Foundation.
The novel was released after his death at the age of 72. He must have been feeling his age while writing as a recurring theme after Hari turns 50 is his rumination on his age and the limitations it imposes. He certainly provides closures for all the nuances and subtleties for the rest of the series. He also goes to great lengths to demonstrate the team-centric nature of the discipline. The tale also relates political and social media realities of playing Cassandra.