Moments subpages are Spoilers Off. You Have Been Warned!
- After finding Ajak dead, Sersi and Sprite are left in grief-stricken tears for their fallen friend who was like a mother to them. Sprite casts an illusion of her last visit with Ajak, which was of them dancing together in Ajak's kitchen. She then tells Ikaris it was the last time she saw her before leaving for London, as Ajak could tell she was lonely and thought living with Sersi was best for her.
- Ikaris is clearly heartbroken for his indirect murder of Ajak. As he tries to cover up her death, he’s so overwhelmed with emotions, his laser eyes come up and damage part of Ajax’s farm.
- Gilgamesh's death. As he passes away in Thena's arms, he begs her to remember what he told her long ago, with Thena unable to do anything but sob at the death of her longtime partner. A solemn cremation is held with Karun reciting the last rites, and Thena scatters the ashes in the Amazon River the following morning.
- When the group asks Druig if he knows about Phastos' whereabouts, Druig dryly tells them not to bother searching for him, claiming that Phastos gave up on humanity long ago. The answer to that claim is immediately made clear with the very next flashback to August 1945, complete with a nuclear mushroom shot; there, a horrified Phastos sits in the ruins of Hiroshima, heartbroken that his work in allowing humanity to advance resulted in a devastating weapon. To be clear, he didn't actually give them the atomic bomb. Phastos introduced humanity to nuclear fission, which is a crucial development in energy production and can lead to scientific advances in unlocking many secrets of the universe. But, like so many others, humans found a way to turn such valuable knowledge into a weapon of mass destruction instead.Phastos: [Sobbing to Ajak] Druig was right. Our mission was a mistake. These people... They're not worth saving.
- The Reveal that Ikaris had Ajak killed for wanting to stop the Emergence, leading to him turning on the other Eternals, with Sprite joining him out of misguided love for him. While Ikaris stands by the Celestials, it's made clear he doesn't enjoy any of it. Lying to the others, killing Ajax, fighting his former friends and allies... it all pains him, even if he thinks he doing the right thing. He pleads for them not to fight him and to simply join him and make the best out of the situation.
- The shock of the entire group to realize everything they had believed about themselves was a lie:
- There is no "Olympia" that's supposedly their home that they've been waiting literal centuries to return to. They aren't heroes who are protecting innocent lives from monstrous creatures but instead aiding in the genocide of billions of people for every newborn Celestial. Plus, they each have millions of years' worth of memories they don't recall because, after every birth of a new Celestial, they get a full memory wipe and are sent to start the cycle all over again on a new planet. The discovery of it affects all of them as they realize their whole lives, existence, and mission have been one big lie.
- As a side note, early on in the film, when Thena's Mahd Wy'ry kicks in and Ajak advises her to let her wipe her memory so she can keep her sanity, Thena tearfully begs her not to as she simply wants to remember her whole life. Turns out, she actually wasn't the whole time for millions of years.
- And Ikaris has been living with this for thousands of years, lying to his friends and loved ones all along, knowing that this is just another job they're doing and that Earth will inevitably die. No wonder he was looking forward to dying — and, ultimately, committed suicide.
- It's also the reason why he left Sersei for many years.
- After killing Gilgamesh, and achieving sentience, Kro reveals the Deviants' side of the story. There's no malice in what they do, they're simply trying to survive like any lifeforms, and in their eyes, the Eternals are slaughtering them for reasons they legitimately can't understand. Kro then mournfully notes how they were used and thrown away by Arishem just to fulfill his own ends, not entirely unlike the Eternals.
- Sprite appears to be like Peter Pan, never growing up. But Kingo figures out that she's actually Tinkerbell. Why? Because Tinkerbell was in love with Peter (who Kingo says is "Ikaris" while Wendy is Sersi) who loved Wendy, and he simply didn't return Tinkerbell's love. He knows that Sprite is in love with Ikaris. Sprite openly asks why she was made to be an unaging child; she just wants to grow up like an adult and live a properly full life.
- Kingo leaves because he believes the Emergence should happen (pointing out how stopping the Emergence will prevent many others planets and lives from forming) but he also refuses to fight his fellow Eternals. Karun goes with him, and, knowing if the Emergence happens he will die along with everyone else on the planet, says that he is honored to have known them, and thanks them for all they've done for humanity.
- When Ikaris seemingly kills Druig, Makkari (who's deaf and understandably mute as a result) gives her only verbal sound in the whole movie. A horrified scream at losing the Eternal she was easily the closest to. Thankfully, Druig turns up later unharmed, but the moment proves to be gutwrenching nonetheless to see the normally silent Makkari actually scream in grief.
- Ikaris becomes overwhelmed with guilt for his actions and kills himself by flying into the sun. The fact that this echoes the myth of Icarus, which a previous scene states that Sprite made up, makes his death a twisted homage of sorts to a friend who loved him.
- Sprite probably wished she never gave him the idea.
- Tiamut's demise is played a bit more tragic, even the Eternals feel genuinely sorry about killing a newborn Celestial. It's made even worse by the fact that they originally intended to spare the being by simply putting it to sleep until they could either evacuate Earth or find a safer, alternative option to awakening it without killing anyone - until Ikaris interfered and messed up their plan.
- Since Sprite is no longer an Eternal, thanks to Sersei, she wasn't taken along with the other surviving Eternals by Arishem. This means she could do nothing but just watch him take them away.
