Hohenheim of Light

Beneath an abandoned church that once served a forgotten faith, the homunculi Sloth, Wrath, Gluttony, and a caged Lust wait as Lyra and Rose descend the hidden stair to join them. In Central, a livid Mustang confronts Edward and Alphonse for bolting without him, yet Armstrong's gentler manner draws out the brothers' claim that Fuhrer Bradley and his secretary Juliet Douglas are both homunculi woven into the Philosopher's Stone conspiracy. Sheska, who had feared Douglas was an alien, takes odd comfort in the news, while the brothers keep Alphonse's own status as a Stone a secret.

On the road back to the Rockbell house, talk of Edward's lost pocket watch leads Mustang to confess that red stones once acted as transmutation amplifiers during the Ishval campaign, an admission that nearly turns into a brawl. At home the brothers find their father returned, and Edward greets the reunion with a fist. That night Hohenheim quietly lays out the grim mechanics of the creatures to Mustang: born shapeless, they gain human form only by devouring lives through red stones, they cannot perform alchemy, and they issue from the far side of the Gate. He tells Alphonse that reversing equivalent exchange could restore his lost body, though he cannot manage it himself.

By morning Hohenheim has slipped away. Hidden in the Rockbell basement, the brothers piece together that the homunculi engineered the Ishval war to force the making of a Philosopher's Stone, and Sheska's careless mention that Hughes died for learning too much shatters them. Pinako defends Mustang's silence as a shield against vengeance, but a bitter Edward swears to hate the colonel from that day forward. At the church, Hohenheim unmasks Lyra as Dante herself, the ancient soul steering the homunculi, and bargains the secret of her rotting flesh for his sons' safety. In Resembool, Edward steels himself for a ghastly errand, opening his mother's grave to claim a weapon against Sloth.

Hohenheim returns and reveals to Mustang that homunculi are born formless, feed on lives through red stones, cannot wield alchemy, and come from beyond the Gate. The Elrics finally learn that Maes Hughes has been dead since they left Central, and that the creatures provoked the Ishval war to spur a Philosopher's Stone. Hohenheim exposes Lyra as the vessel of Dante, the mastermind behind the homunculi, and trades the truth of her decaying body for a promise to spare his sons. Edward resolves to desecrate Trisha's grave for a means to strike at Sloth.

Lyra's opening remarks about a faith stamped out of Amestris strongly imply Christianity, a reading reinforced two episodes later when Izumi refers to the dating system once tied to an ancient religion. The episode title names Van Hohenheim, and the story distinguishes the man from the chapter that carries his epithet.