Foundation season 3 episode 3 was released on July 19, 2025. In the episode titled, When a Book Finds You, the storyline begins with Brother Dawn’s secretive meetings to help stop The Mule and ends with a dramatic conclusion. That includes a revelation and the introduction of a new religion that changes everything for Brother Day’s potential escape plan.Disclaimer: The following article contains spoilers from Foundation season 3 episode 3. Reader discretion is advised.This revelation in Foundation season 3 episode 3 involves Demerzel's disturbing actions, as she tells Day that she erased Song’s memories and sent her back to her home in the Mycogen district. She did this after Song found out about Demerzel’s true nature, and Song later revealed to Demerzel that she is a follower of a forbidden religion that made her a threat to the group.The episode ends with Day’s escape plans now dead in the water and with significant concerns about his future after the loss of his consort.Brother Day tells Song about Demerzel’s true nature inFoundation season 3 episode 3 View this post on Instagram Instagram PostThroughout Foundation season 3, Brother Day has found himself increasingly terrified and trapped by his imperial obligations as well as his mortality. After focusing on Brother Dawn and his secretive plans, Foundation season 3 episode 3 introduces Day and Song in the middle of the soldiers' barracks.The two then speak to Mavon with a proposal, the latter will help the former escape in exchange for Day helping Mavon’s family gain the freedom they want. However, while sceptical, Mavon continues to hear them out, although it seems as if he is leaning towards rejecting them.But Day also promises Mavon enough riches to buy a planet and imperial nanites to cure his daughter of her terminal illness. This seems to change his mind as Mavon agrees to consider their proposal, sending Day and Song on their way.As the two are walking back to their villa, Day spots Demerzel in the distance and asks Song to stop to allow Demerzel to pass by so they can continue their conversation. Song notices Day’s fear of Demerzel and his insistence on calling her ‘it’, and questions why he does that.While Day initially refuses to tell her, he eventually opens up and tells Song that Demerzel is a robot. Song refuses to believe that, as robots were said to have died out, but Day reveals that she is the last of her kind and the more she learns about Demerzel, Song realizes Day is telling her the truth.Foundation season 3 episode 3 ending explained: Demerzel erases Song's memories and sends her awayA still from the trailer (Image via YouTube/@AppleTV)Having now learnt the truth about Demerzel in Foundation season 3 episode 3, Song and Day are packing to leave, but the latter realizes that the former’s mind is elsewhere. That is confirmed when Song voices her doubts about their escape plan. She even suggests that Day stay under Demerzel’s protection, but before she can convince him, Demerzel orders Day to join Dusk at the palace.While Day’s back is turned, Song sends a secret signal to Demerzel, but it’s ignored at first. However, at the end of the episode, it is revealed that Demerzel did not ignore the signal, recognized it, and took immediate action. She tells Day that she sent Song back to her home in the Mycogen district after erasing her memories of her time with Day and everything she learnt.Demerzel tells Day that she did this because Song belongs to a secret religious sect called the Inheritance – a forbidden religion that worships robots. It leaves Brother Day alone without his consort, his escape plan effectively in tatters, and his future in question.Not only that, Demerzel's inscrutable expression even questions whether Song is alive and if Demerzel’s claim of merely erasing Song's memories is the complete truth.Foundation season 3 episode 3 sets up far more than anybody was expectingA still from the trailer (Image via YouTube/@AppleTV)From the very beginning of the Foundation season 3, the Mule continued to showcase why he's become the galaxy’s most feared threat and episode 3 is no different. His first appearance in the episode shows him hosting a party on Kalgan, which Captain Pritcher, Bayta and Toran gatecrash.However, Pritcher is mentally knocked out by The Mule, who invades his mind and demands information about Gaal Dornick. Pritcher retreats hastily to his ship and leaves, while Bayta and Toran attempt to finish what Pritcher started, to get information about The Mule.They succeed, although while Bayta convinces Magnifico to escape with them, Toran has his hand flayed by The Mule as he was trying to distract him. The two eventually escape with Magnifico, jumping to safety even after a missile hits their ship.Unhappy that his companion was ‘kidnapped’, The Mule proceeds to hijack a jumpgate in an attempt to continue to establish his control on Kalgan and find his peculiar companion. Meanwhile, in another part of the world, Brother Dawn continues to operate with independence and manages to establish a secret line of communication with Gaal in Foundation season 3 episode 3.He even tries to advocate for containing The Mule via an Enclosure on Kalgan. But Brother Day refuses to call an emergency council and Dawn settles for surveillance on The Mule instead.Interested viewers can watch Foundation season 3 on Apple TV+.