At long last I have come to the end of the Foundation series, at least the books which were written by the Grand Master himself, Isaac Asimov. Forward the Foundation is another prequel book which actually fits in chronologically between Prelude to Foundation and Foundation, bringing the series full circle. This is true in at least one other respect because the book returns to a series of shorter stories rather than a full-length novel, much like the original Foundation novel. Having read the books in publication order it felt like a very appropriate ending to the series, bringing the timeline and story back to where it all began, tying the series up rather nicely from a thematic standpoint at least, even if plot wise it's still left open-ended from Foundation and Earth.
What I really noticed about this book is that it had a much grimmer outlook than all the other books. I did some digging and found out this was one of the last books Asimov read before he tragically passed away in 1992, which may explain the darker tones. I noticed that throughout the book Hari Seldon consistently complains about getting old. Whether he's forty at the start of the book or seventy towards the end, he constantly frets about his advancing years and worrying that he won't be able to finish psychohistory in time for it to be of any real use. Personally I suspect it's because Asimov felt he was towards the end of his life and so his own concerns over getting old started to bleed over into the character of Hari Seldon. And considering Seldon's described as a prolific writer and remembered as a kindly old man venerated by millions, I think Seldon started to reflect some of what Asimov saw in himself.
The overarching story is, as you probably guessed, Seldon's struggles to complete psychohistory to a functional level in time that they can prevent, or at least ameliorate the fall of the Galactic Empire. Through the book we see Seldon walk the halls of power in the Empire, watch helplessly as the edges begin to fray, and then see Trantor itself, the Eternal Planet, begin to go into extreme urban decay that will eventually rot the very heart of the Empire. It's very atmospheric to say the least and although it's a little extreme to see an Empire fall in a generation, (And previous books had explicitly stated the Empire hangs on in some form for another two hundred years or so) you really get a feel for the decline and the desperation to do something to keep the galaxy from sliding into perpetual barbarism.
Overall I really liked this book and while I am aware that other authors continued the Foundation series after Asimov's death, I actually want to hold off on that and read more of Asimov's work first. Specifically the Robot and Empire novels which promise to shed far more light on the history of Asimov's universe. Coming to the end of the series overall, I'm very happy that I read it. With the exception of Foundation and Earth. But really that's how life goes if we're being perfectly honest. Sometimes people write absolutely terrific books, sometimes they write horrible books, and often they write both. I'm still not sure exactly what Asimov was trying to do with Foundation and Earth, but I get the feeling with his change in tack in the later novels that he realized it wasn't working and shifted back to what had made Foundation great. If you're a fan of space opera and haven't already picked up this book series, I highly recommend (most of) it.