A flashback of Mustang and Hawkeye during the Ishbal War, with the latter burying a child war victim. Mentioned then was a bit of Hawkey's past with her father, his study of Flame Alchemy, and Mustang eventually agreeing to burn part of the tattoo on her back so that its secrets regarding Flame Alchemy are no longer comprehensible.
Continuing off from the last time, we learn that one of the two cahracters is indeed Envy masquerading in disguise. In any case, Hawkeye was lying about how Mustang calls her "Riza" when they're alone together was a much more clever way of baiting Envy out. Then the real Mustang made his timely arrival and started scorching Envy to death, and getting his chance to take revenge.
Hawkeye steps in to stop Mustang before he could finish off Envy, and then Ed and Scar lecture him a bit about how his lust for revenge has consumed him. After hearing what they had to say, Mustang agreed to take the high road and act like a protagonist should, they got through to Envy by pointing out how he's jealous of humans and their will to never quit, causing him to commit suicide instead.
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