Chapter 23: Knocking on Heaven's Door

Five months on, Edward and Alphonse resurface in Resembool with a new maturity and word that their alchemy training is done. Winry and Pinako welcome them home with a meal, but when asked to recount their apprenticeship, the boys are struck speechless with dread at reliving it. Their growth shows plainly, though, when neighbors ask them to fix a storm-damaged shed and they raise an entire new building in seconds. Even so, they note how far they remain from their teacher, who can transmute merely by clapping her hands together. The scene rewinds to a sparring session in which Izumi fends off both boys one-handed while reading a cookbook, teaching that the circle governs the flow of energy and its runes release that energy in set ways. She explains that circular flow applies beyond alchemy, as in combat, and that accepting and using it to create is what makes an alchemist, before warning gravely that life and death are part of the same circle and the dead must never be brought back. When Al asks how she transmutes by clapping, she says she herself becomes the runes, and hints the boys might do the same should they ever reach the truth.

Back in Resembool, the brothers turn their new knowledge toward a forbidden goal, secretly researching a formula for Human Transmutation. Near summer's end, Edward perfects it, and the boys eagerly assemble their ingredients and the elaborate array to see their mother again. After each adds a drop of blood to fabricate a soul from their shared lineage, they place their hands on the circle and begin. Almost at once it goes wrong. The energy darkens, and Al realizes his body is being unmade piece by piece; Ed finds his own leg deconstructing as the transmutation rebounds on them. Al screams for help and vanishes with a sharp crack, and Edward is cast into a vast white void holding a single engraved stone tablet.

A formless white being greets him, naming itself God, the Universe, the Truth, the all, the one, and Edward himself. The tablet splits open into a dark void of grasping shadow hands around a single eye, and the Truth drags Ed inside, mocking that this is what he always wanted. Floods of biological, alchemical, and historical knowledge pour into his mind as his body is pulled apart molecule by molecule, and as the pain overwhelms him he glimpses a figure shaped like his mother reaching out, only to be thrust back into the white expanse intact. Ed realizes his formula was not wrong but incomplete, and begs to enter the Gate once more, but the Truth says he has seen all his toll allows, and takes his left leg as payment, reconstructing it on its own body. Waking bloodied on his own floor with everything below the knee gone, Edward finds only Alphonse's empty clothes and, at the circle's center, a grotesque half-formed creature that stares blankly, coughs blood, and dies. Desperate, he drags himself to a suit of armor, scrawls a blood seal inside it, and, offering whatever the toll demands, claps his hands to call his brother back. Within the Gate, the Truth watches Edward's right arm slowly reconstruct and calls the boy a fool.

The chapter shows the Elrics completing Izumi's training, then depicts the forbidden human transmutation that destroys their bodies: Alphonse is taken into the Gate and Edward loses his left leg. Confronting the Truth, Edward gains vast knowledge, sees his formula was incomplete, and finds the failed creation dies. He then sacrifices his right arm to bind Alphonse's soul into a suit of armor.

The boy who arrives to recruit the brothers for repairs is likely the same one who greeted Edward in the fields in Chapter 9. While designing the transmutation formula, Ed sits at his father's desk exactly as Hohenheim once did, echoing his earliest memory of the man. In one panel the Truth's pose is not properly mirrored when reflected in Edward's eye, with the left and right arms reversed.