The spoiler is in here.
FLCL was great. At first, it seems like complete and utter nonsense and it is. But usually in the end, there's a greater message. It might be comforting or deep but it's always there and it can be a great message indeed.
Laws and PromisesThe episode opens with Edward being impaled by Envy while Rosé and Alphonse look on helplessly. The scene then changes to just outside the Führer's estate where Riza is being taken to Central Headquarters to be interrogated about what's going on with Mustang. The car Riza is in crashes with an oncoming car driven by Archer. He exits the vehicle and sees Riza there in the car and opens fire on her. She is hit in the shoulder and she fires back. Meanwhile Mustang and Pride are fighting in the blazing wine cellar. Pride stabs Mustang's left shoulder with his sword, pinning him to the wall. Just as Pride is about to finish Mustang, Selim, Prides adopted Son, barges in. Selim reveals from his bag the "treasure," wrapped in cloth, and Pride chokes him in anger and throws him across the room. Mustang frees himself, finds the skull of Pride to be the "treasure", grasps it with his left hand, and draws a flame circle on the hand holding the skull using his own blood. Pride is held in place by the skull and repeatedly burned by Mustang.Back in the underground city, Gluttony is feeding on Al. Alphonse uses alchemy to activate the stone, causing Gluttony's jaw to partially dissolve. Alphonse then moves over to Edward's body and states that Edward's soul is probably still at the gate. He then prepares a transmutation to heal Edward's body and reattach his soul. Six giant transmutation circles appear on the wall. Envy leaps toward Alphonse in a futile attempt to stop him. The transmutation carries both of them away.Back at the estate, Mustang has reduced Pride to a pool of liquid (liquified Red Stones that Pride had consumed). He sets the liquid on fire and then drops the skull into the flames. Mustang takes Selim and leaves the building. Archer has just arrived to the mansion and aims his pistol at Mustang. Riza runs to the estate and sees Archer. She shoots him through the chest (which is still flesh and blood), killing him. She continues running to the building and sees Mustang collapsed on the porch in a pool of blood. She arrives there and calls out his name several times and begins to cry and scream in despair.At the gate, Ed's soul briefly sees Alphonse's armor body appear and then disappear as the Philosopher's Stone is exhausted. Then Envy appears and meets Ed's soul at the gate. Ed reveals where the gate goes and that Hohenheim is still alive on the other side. Envy goes into the gate to kill Hohenheim, but the creatures inside the gate attack Envy and start to dissolve him. He gets them off of him by transforming into Ed. In his anger, he transforms again, first to his true form, and then to a giant serpent, which may be interpreted as either a Leviathan or a literal Ouroborus. The gate closes and Edward's soul departs the area of the gate.Ed reawakens in the underground city, with Rosé trying to wake him. His body is healed, and he has all of his limbs. Dante, meanwhile, flees to the surface in the elevator to Pride's office. She expects to find him there and plans to have him go down to the underground city to kill Ed. Suddenly, a mindless Gluttony breaks into the elevator by chewing through the floor. Dante attempts a transmutation to defend herself, but when the elevator reaches Pride's office, it opens with no one inside. Ed asks Rosé to return to the surface with the now-helpless Wrath, and then begins a transmutation with the aim of pulling Alphonse's body and soul from the gate by sacrificing himself.The episode then moves forward several months and Scieszka, writing a letter to Winry, narrates, summarizing what has happened since. Since the death of Führer Bradley, Lt. Colonel Armstrong and the General who commanded the Eastern Headquarters organize a ceasefire. They jointly organize the handover of political power from the military to a National Assembly. Roy Mustang has lost his left eye and is in bed, slowly recovering from his injuries. Riza is taking care of him, as always. Riza blames herself for not arriving in time to protect Mustang, but Mustang tells her that nothing is perfect, not even the world, but that is why it is beautiful.Alphonse Elric, restored to his original body.The Ishbalans have been allowed to return to their city and rebuild it. Alphonse is shown to now be alive. He has returned as a ten-year-old boy with no memories beyond the day he and Edward transmuted their mother. Izumi, Pinako, Winry, Scieszka, Rosé and her child, and others meet at Pinako's house, where Alphonse is staying. Izumi attempts to explain to Pinako how Alphonse could come back in terms of Equivalent Exchange. Pinako tells Izumi that she and Winry constructed automail limbs (originally intended for Edward) for Wrath, but that Wrath has run away. Later, during dinner, Alphonse asks that Izumi train him in Alchemy again so that he can find Ed. Alphonse leaves by train with Izumi and says goodbye to Winry, Rosé, and Pinako.The scene then shifts to our Earth. It is now 1921 in Munich. Hohenheim is working with an occult organization known as the Thule Society in an effort to reach Amestris/Shamballa. In reality, Hohenheim is working with the group in an effort to find a way to return Edward to his world. Ed has reconciled with his father and has been living with him. Ed's body is missing an arm (and probably a leg too), which he has replaced with prosthetics, since automail does not exist in our world. Edward is studying rocketry in an attempt to get home. He is about to leave for Transylvania (modern-day Romania) to work on rockets with Hermann Oberth, to reach space, in an attempt to return to his world and Alphonse. He and Hohenheim discuss Equivalent Exchange and how it relates to his attempt to restore Alphonse. Hohenheim offers the idea that their Equivalent Exchange was their journey and the four years of hard work that they put into restoring themselves.We see Edward and Alphonse in different worlds on different trains. Alphonse narrates a montage sequence revisiting many characters. These include Tucker, still trying to bring back Nina; the Ishbalans, rebuilding; Mustang and Hawkeye, shopping at a market; Wrath, lying on the ground under a tree; Gracia and Elysia Hughes, with Scieszka, laying flowers at Hughes's grave; Pinako, with Rosé and her baby, at their house; Russell and Fletcher Tringham, working in a lab; Winry, working with Dominick and Paninya in Rush Valley; and finally Armstrong and Breda, entertaining a group of soldiers that includes Fuery, Falman, and Havoc. Al explains that while he and Ed used to think that Equivalent Exchange was a fixed law that could explain anything in the world, they no longer believe this to be the case. The world is too complex and imperfect for one law to ever explain everything. But in spite of that, they still believe in Equivalent Exchange in a slightly different sense: that no one can gain anything without giving something of themselves, and conversely that anyone who works toward something will be rewarded, even if it's not in the way that they expected. Al says that he no longer thinks of Equivalent Exchange as a law of the world, but rather as a promise between himself and Ed that they will someday find each other again. The series concludes with Edward and Alphonse reaching out to the sky towards one another.