Apple TV's Foundation is based on an iconic series of sci-fi novels by Isaac Asimov, but the live-action adaptation is more faithful to certain elements of the source material than others. For instance, the massive time jumps and the centuries-long arc honor the books perfectly, even if things like the Clone Dynasty are original to the show. There are, however, certain creative choices made at Apple TV that often fall somewhere between faithful and trailblazing.
Asimov's first Foundation book was published in August 1951, and he went on to write several sequels and prequels to flesh out his sprawling space opera. Foundation season 1 premiered in September 2021, 70 years after the author got the ball rolling. As such, countless readers had experienced the novels during that multi-decade gap, and it's clear the show's writers were among that throng. There is a moment in Foundation season 3 that powerfully acknowledges a minor line from the books, which will surely have a huge impact on season 4's storyline.
Issac Asimov gently referenced the superweapon that Apple TV's Foundation introduced in season 3
Played by Alexander Siddig in the show, Ebling Mis is largely believed to be the best psychologist of his generation, even if he does fall short of Hari Seldon (Jared Harris). The books, however, treat the character's intellect quite differently, as he drives himself to the point of insanity trying to make sense of a specific part of Seldon's psychohistory equations. During one of his rants toward the end of 1952's Foundation and Empire, he talks about specific factors that could derail Seldon's plan, like the Mule.
Another scenario revolves around the possible repercussions if "a new weapon were to be invented by forces outside the Foundation, capable of withstanding all the Foundation's armaments." Although he admits it would cause "ruinous deviation" from Seldon's plan, Ebling Mis goes on to clarify that he is merely speaking hypothetically, and that such a weapon does not exist within the world of the books. Asimov also didn't pay off this line in later installments.
Fast forward to 2025, and Foundation season 3 revealed something in Empire's hands called the Novacula, an immensely powerful device that harnesses the power of a black hole to inflict Death Star-levels of devastation upon unsuspecting planets. There is no known defense against the Novacula, nor could it possibly have been accounted for in Seldon's plan. It sounds oddly like the weapon Ebling Mis was speculating about in Foundation and Empire, doesn't it?
How Foundation season 3 introducing the Novacula will impact season 4
The Novacula is such a narrative gamechanger for two reasons, but first, it's important to understand that both Foundation season 3 and the second book in the series end at pretty much the same point. That said, there are some very pivotal differences, beyond the Clone Dynasty running riot in the show and not existing at all in the books.
My first point does tie into the Clone Dynasty, in a way. By the end of Foundation and Empire, the Empire itself is in a much worse position than its Apple TV counterpart. Trantor has been completely abandoned, and the Imperial infrastructure has been moved to a new world called Neotrantor, a smaller and less developed planet consisting mainly of farmland, led by an old and confused emperor. The live-action adaptation has really played down Empire's gradual decline, but the Novacula puts them in a surprisingly powerful position moving forward.
That said, the existence of the Clone Emperors in the show is the perfect vehicle for realizing the theoretical weapon that Ebling Mis briefly used as a talking point in Foundation and Empire. It takes Terrence Mann's Brother Dusk and the specific blend of inter-emperor rivalry and an understandable resistance to ceremonial execution for him to have the Novacula brought into existence. In other words, it required something from the TV show's canon to provide the most organic way for the Novacula to enter the new version of the story, which, in itself, was only ever a vague concept in the books. It's twisty, but the blueprint is there.
So, not only will the Foundation be facing a threat in Foundation season 4 that is unprecedented in the larger franchise, but the threat itself unexpectedly strengthens an opponent that should be far further along on the path to obscurity. Moving forward, this authentic-feeling but notable divergence from the source material makes it far more difficult to guess what'll happen when Foundation returns, even for those who have already read the books.
Another big Foundation and Empire change will affect Foundation season 4
In the books, the Mule hides behind the persona of Magnifico Giganticus, an obsequious clown who has supposedly escaped from the Mule's oppressive rule. However, the final pages of Foundation and Empire reveal that the clown IS the Mule. Foundation season 3 alters this reveal, so that Magnifico is a separate character, a real clown. The person everyone believes to be the Mule is just a random guy being controlled by Bayta Mallow, who is ACTUALLY the Mule, and has been all along.
Bayta's surname is Darell in Foundation and Empire, but she is otherwise very similar to her book character until the big season 3 reveal. Other than her turning out to be the Mule in the show, the other most notable difference is that Bayta never returns after the second book, whereas the Mule does. By making Bayta the Mule and having her survive the events of the Foundation season 3 finale, that means she can continue to be part of the story for longer than she did in the source material, which will also mean rewriting Asimov's work.
Foundation seasons 1-3 are streaming now on Apple TV. Season 4 has no confirmed release date, but is expected to arrive in 2027.