Episode 24, "Inside the Belly"
Synopsis: Gluttony goes on a rampage, trying to devour Roy into his eye Gate. Roy manages to escape with Riza in a car, taking Ran Fan with her, while Ed, Al, and Ling stay behind to fight. Envy arrives to retrieve Gluttony, but a new fight begins, and Gluttony accidently swallows Ed, Ling, and Envy. Roy attempts to enlist the help of General Raven at Central HQ, but it's revealed that he and a number of high military officers are in on the homunculi's plans, and the Fuhrer appears before him.
For some reason, when I watched this episode the first time with the dub, on Adult Swim, I absolutely loathed the job done on it. But when I rewatched it, it sounded a lot better for some reason. I may have to make a habit of that.