If Hughes is watching from heaven, he must be so proud of his best friend.
Shortly after the end of the Ishval war, a young Riza is making a grave for a child killed in the battlefield. Mustang is nearby watching her, calling her so that they can come back. Even though the war is over, Riza said that in her heart, the war will never ever end and she never thought that her father's research, flame alchemy will be used to kill people. To at least atone for this, she asked for Mustang to burn the secret of the flame alchemy on her back so that no one will ever learn to use flame alchemy.
Back to the cliff hanging ending of Episode 53, Riza pointed her gun to Mustang. She said that when they are together, Mustang calls her Riza instead of Lieutenant. With this it irevealed that it is actually Envy posing in as Mustang. Riza uses her two guns and shotgun to shoot at Envy successively.
Envy then attacks Riza on shoulder, therefore injuring her. This is the time that Mustang finally founds Envy and again burns him to death. Envy is really wounded that he transformed back to his larvae form.
Mustang steps on the weakened Envy and is about to give him the final blow but Riza stood up and pointed her gun to Mustang and tells him that she will take care of Envy instead. Mustang is so raged and ordered her to drop the gun but suddenly, Ed and Scar appears. Ed gets Envy using his alchemy from Mustang's foot and this makes the Colonel really enraged.
Roy warns Ed that if he will not hand over Envy, he will not hesitate to burn his arms along with Envy. Ed says it is fine and that he will fight him head on but first, he has to look at the mirror and see what has happened to him. He is so full of anger right now. Ed asks him if that is the look he wants to have once he will stand as the Fuhrer President. Riza also said that what Mustang is doing right now is to satisfy his own hatred, not for the country nor for his subordinates. With these words, Mustang finally calms down and apologizes to Riza. He doesn't want to loose her irreplaceable subordinate, after all.
With the turn of events, Envy taunts everyone to attack each other but nobody is doing nothing. Ed then states that Envy is jealous of humans because even if in the worst situations, humans can stand up. Envy gets crazy and he feels disgraced that the person who can understand him is Ed, a human being. He then admits that he in indeed envious of humans followed by committing suicide by removing his own philosopher's stone.
Back in Central HQ, takes command of the central soldiers to defeat the immortal army. Sloth also freed himself from Alex's impaling and again sets his eyes on Olivier. Alex stops Sloth but is having a hard time because of his injured shoulder. Sloth attacks Alex as he is on his way. The soldiers get worried but Olivier says that is okay, his brother can handle it. Alex uses Sloth's attack to give his shoulder the repair it needs. This then begins his all out attack to the homonculus.
At the front gate, the one in charge reports to the general that Briggs has a tank in their possession. The general orders for an all out fire even though the civilians are still for evacuation. Before the order can be relayed to the gate, Bucaneer arrives with the help of Falman who is still familiar with the Central HQ. They dug out a tunnel inside HQ so that they can enter easily. It is also revealed that tunnel was dug by Izumi Curtis.
Deep underground, Hoenheim arrives where Father is.