Episode 3 splits into Trantor and Terminus halves, without going back and forth between the two. So, in Part A, we have the Emperors on Trantor as they transition to a new, baby, Brother Dawn, the now-grown up Brother Dawn takes on the mantle of Brother Day, the aging Brother Day becomes Dusk, and Dusk “ascends” (is vaporized).
However, Demerzel, their robot consigliere, has been serving the emperors since Cleon I, the emperor who originally cloned himself rather than having a family member succeed him, and has routinely watched Brother Dusk grow nostalgic and uncertain in his last years. She also serves as a creepy ageless mother for the emperors, singing them lullabies in the cloning tanks, and also running the empire alongside them.
The outgoing Brother Dusk gets a wild hair that Hari Seldon might be right about the downfall of the empire which his clones insist must be ridiculous. Besides being the central character of the series, its not obvious why Brother Dusk suddenly thinks of the Foundation, besides the space bridge has apparently never been rebuilt since it was blown up in Episode 1. Furthermore, if four genetically identical men disagree on something, won’t they rehash the same argument over and over again? Oh, wait, there’s a sneaky, ageless robot who’s watching them do exactly that, and the empire has not been good to robots.
Meanwhile, on Terminus, the colonists arrive without Hari Seldon, Gaal Dornick, or Raych, but still everything seems to be working out as Seldon planned. As years pass, a new generation grows up on Terminus under the shadow of a mysterious floating object — named The Vault for reasons only known to those who’ve read the book — in the nearby hills that has a “null field,” a human version of those fences that interact with sensors in dog collars, surrounding it. Salvor Hardin, (Leah Harvey) a planet park ranger, notices irregularities with it and believes through gut feeling that Hari Seldon might be trying to contact the colony through it.

Salvor Hardin also has an intuitive connection to the Vault that feels a little askew in such a math-oriented story. Curiouser and curiouser, she’s like, the entire army. Nobody else open carries, but when warships from Anacreon (a planet whose ambassador was executed last episode) pop up on the radar, Salvor has a rather one-sided argument with the local Devil’s Advocate before she is captured on patrol by a woman carrying a bow and arrows, of all things.
How will Salvor save the Foundation? Will she give in to the travellin’ salesman she loves, as he tries to tempt her away to distant planets? Stay tuned for episode four!