Attack on Titan, since it first aired in 2013, has only kept getting better and better with each new season. And the third season, particularly Part 2, may just be the best one yet.
While there were a lot of moments responsible for making Season 3, Part 2 what it is, such as Commander Erwin's inspirational speech and suicidal charge that won the battle to reclaim Shiganshina, the secret of what was in the basement under Eren's childhood home was teased from the very first episode. Eren's father, Grisha, promised to show him what he was hiding in it one day. Of course, things didn't go Grisha's way after the walls collapsed and Shiganshina fell. All the while, the next 50 or so episodes went by while the secret of the basement was dangled like a carrot above the audience's heads. The anime used this time to brilliantly build-up toward the grand reveal, which finally dropped in Episode 56, turning the entire premise of Attack on Titan upside down.
The episode came immediately after the battle for Shiganshina. Eren and his friends successfully regain control of the district after the sacrifice of many of their fellow soldiers. The squad finally arrive at Eren's old home, now a battered wreck, and make their way into the basement. Initially, Eren and co are startled when Grisha's key, which he had given to Eren before his death, doesn't open the door. However, they soon realize the key wasn't for the basement at all but, in fact, for something else altogether -- a locked desk that belonged to Grisha.
Inside, the squad found three journals written by Grisha and a photograph of him with a child and a woman, all of them dressed rather elegantly. Most significantly, however, was a detail as small as the photograph itself. The technology for taking photos did not exist on the island Eren lives on. And, as you'd expect, the characters were perplexed by it -- remaking on how realistic a drawing they thought it was. The back of the photograph had a message from Grisha revealing that humanity had not perished like the Royal Government had led people to believe. On the contrary, the people outside were living a refined, technologically-advanced lifestyle.
The following episodes were dedicated to the information Grisha left in his journal, and how he came to live within the walled island of Paradis even though he was a former citizen of the nation of Marley. It was revealed that humans who could be transformed into Titans, like Grisha, were a particular race called Eldians who, outside of the island, are treated as second-class citizens. The way they were depicted drew a clear comparison with the way Jewish people were treated in Nazi-ruled Germany, a controversial analogy that left audiences divided.
Beyond this criticism, the revelation that other humans lived outside the walls, and with 20th-century privileges, was earth-shattering for the series. For three seasons straight, Attack on Titan led the audience to believe -- through omission -- that either humanity had perished outside the walls, or a few remained outside, planning the downfall of those within the walls. Instead, it is revealed that civilization is thriving, with the people outside living normal lives, completely unlike that of those within the walls who are living in a technology-stunted world, in constant fear of the terrifying Titans.
The biggest implication of the reveal, however, is one that completely changes the tone of things to come. Before this, Attack on Titan was a show about humanity overcoming evil monsters. Now, we know that the enemy is indeed other humans, with the Titans only being mere weapons. Over one episode Attack on Titan, went from being an apocalyptic thriller into a sociopolitical drama. For the main characters, it was one thing fighting for freedom by killing monsters, but completely another doing the same by killing helpless victims. This moral dilemma is now at the forefront of the show.
Through political upheaval, Part 1 had established other human enemies to slowly ease the viewers into this drastic change. However, the basement reveal may just be one of the greatest twists in all of anime. It was expertly executed and was foreshadowed over multiple seasons so that the eventual revelation did not feel like information being pulled out of thin air. The thematic core of Attack on Titan, the answer of freedom, was given a new question. What does fighting for freedom mean when the enemy is no longer a mindless monster? This simple change is what makes the basement reveal so great. After this episode, Attack on Titan was no longer the same, and neither will the experiences of those watching.