From You, 2,000 Years Ago (Episode)

"Were you the one who led me here? You've been waiting this whole time. For 2,000 years... For someone."

- Eren Jaeger appeals Ymir

From You, 2,000 Years Ago (二千年前の君から) is the 21st episode of the 4th season and the 80th episode overall of the Attack on Titan anime, produced by.

Summary
Grisha Jaeger remembers how he killed the Reiss family with his Attack Titan and laments that Eren would not show him everything in store for the future. He warns his son Zeke Jaeger that things will not go his way and that the future Eren has foreseen is terrible. Grisha asks Zeke to stop Eren.

After he does, Zeke is thrown out of Grisha's memories and back into the sandy terrain of the Paths where he sees Eren still chained nearby. Zeke asks if Eren pushed their father into fighting the King of the Walls and thus the rest of the world. Using the power of the Attack Titan, Eren could have shown Grisha specific memories in order to influence his behavior in the past. Grisha could not use the Founding Titan, so the primary reason he stole it was to entrust it to Eren in the future.

Eren thanks Zeke, because this plan was only possible through Zeke bringing him into Grisha's memories. He goes on to explain that he saw his own future through Grisha's memories four years ago.

Zeke recalls Grisha saying how things will not go his way, but knowing he still has control over Ymir he orders her to make Eldians no longer able to have children. She turns and walks towards the Coordinate as Zeke tells Eren that their father wanted Zeke to stop him. Eren struggles against his chains to run after her and Zeke says he does not know what future Eren saw, but he knows Eren did not see everything. For instance, Eren did not expect that he could not use Ymir's powers himself.

Eren screams and rips the chains off, severing his hands, which regrow, and he chases after Ymir. Zeke believes this effort will be useless since the command has already been given so nothing will stop her.

In the distant past, Ymir is a young girl living in a small village when invaders come. She and the other survivors are enslaved and their tongues cut out. One day the pigs escape their pen and Fritz, the tribal leader, declares that if one of them does not confess, all of the slaves will have an eye cut out. Ymir is selected as a scapegoat.

Unable to refute the others, she kneels in front of the chieftain and he tells her that she will be "free." Ymir is set loose to be hunted by men on horseback. Injured from arrows that have struck her, she tumbles down to find a large tree with a hollow at the base of the trunk. She walks inside and slips, falling down a long tunnel and landing in a pool of water below. As she sinks into the water, a spindly fluorescent creature swims up from the depths and aligns several of its tendrils along her spine. A light flashes and a massive Titan rises out of the forest.

Years later, she is now a prized possession. Fritz is pleased with how she has built roads and cultivated the wilds for them. His tribe has grown with her support and as a reward he intends to have her bear his children. He then has her attack Marley.

She has three children with him, and Eldia is raised from a tribe in wooden homes to a kingdom with buildings of stone and trappings of riches. When enemy soldiers kneel before Fritz in surrender, one of their officers rises to his feet with a spear. He manages to throw it before being killed himself, and Ymir hurls herself in the way, taking the blow through her heart. She falls to the ground, unmoving, and does not rise when Fritz commands her to.

Determined not to lose Ymir's power, Fritz has their daughters Maria, Rose, and Sina, consume the body of their mother. He declares that they should have children to continue the bloodline and when they die their spines should be fed to their own children, and so on down the line so Eldia will continue to dominate the world. As the Eldian Empire continues to rule, Ymir carries a bucket in the paths and builds Titans in the sand at her descendants' command, expecting to do to so for all eternity.

In the present, Eren embraces Ymir and tells her that he will end her slavery, saying that she is not a god or a slave, but a person. She has a choice.

Seeing that she has stopped moving, Zeke begins to panic and runs towards them as Eren asks Ymir if she is the one who led him here, suggesting that she has been waiting for two thousand years for someone. In Eren's arms, Ymir trembles and tears run from her eyes.

Outside the paths in Shiganshina District, a long translucent spine connects Eren's head with his body. It is similar to the creature Ymir had encountered in the pool. Then the light of a Titan transformation flashes and the Walls crumble, interrupting the fight between the Paradis Island military and Marley. Hundreds of Wall Titans are revealed and they begin to march, crushing anything in their path. Eren leads them in a new Titan form, that is so gigantic it dwarfs even the Wall Titans.

Armin Arlelt realizes this means Eren has won and taken control of the Founding Titan. The Wall Titans are likely heading out to crush the global alliance forming in Marley. Mikasa Ackermann struggles to accept that this could mean Eren really did come home to them, but Armin then realizes that the number of Wall Titans is excessive for that purpose.

As he talks to Mikasa, all Subjects of Ymir, no matter where they are in the world, are briefly pulled into the paths. Eren speaks to them and explains that he is talking to them through the power of the Founding Titan. He has undone the hardening on all the Walls and sent the Titans out to march. Eren intends to protect the people of Paradis Island. Since the outside world wants to exterminate all Subjects of Ymir, regardless of whether they live on Paradis or not, he will instead use the Titans to trample every inch of the world beyond the island until nothing is left alive.

The Origin of Titans
''According to legend, the Founder Ymir obtained the Power of the Titans when coming into contact with "something." For generations, her blood and power were passed down by the Eldians. However, the identity of that "something" which began it all remains unknown. It may have been some type of pathogenic parasite, a god who pitied the Founder Ymir and gave her power, or something else entirely.''