Edward's father, Van Hohenheim and a few other people are in a horse-drawn carriage which heading to the countryside. Suddenly, the carriage is overtaken by a group of bandits. One of the bandits made several attempts to shoot Hohenheim, but the bandits run off in horror when they discovered that their bullets seem to have no lasting effect upon Hohenheim's flesh.
In Central City, Gluttony has his permission from the Fuhrer to eat Ran Fan but Ran Fan immediately rescued by her master, Prince Rin Yao. This leads to a battle between Rin Yao and the Fuhrer. The Fuhrer summons Gluttony, and Gluttony pummels Rin Yao and Ran Fan through the window of a nearby abandoned building. Rin Yao tries to escape with injured Ran Fan by releasing light grenade to blind their enemy's visual. However, his path is suddenly blocked by a sword thrown by Wrath (the Fuhrer), who has removed his eyepatch and reveals that his Ouroboros-marked left eye can still see.
Meanwhile, the Elric brothers have to keep battling with Scar until the Homunculus appears. While Edward is debating with Scar regarding his judgement for his killing, Winry arrives at the scene. Edward doesn't know that Winry is there and asks Scar for his reason of killing Winry's parents who have helped the Ishbalans and also him. Winry overhears everything, demanding Scar to answer her; she grabs the gun beside her and aims at him.
An explosion suddenly occurs in an abandoned building, and Rin Yao successfully escapes with injured Ran Fan on his shoulder. From the building, the Fuhrer is watching their escape and amazed with the usage of the flash grenade, smoke grenade and a hand grenade. He admits to Gluttony that he is not young anymore and his body can't keep up with the chase although he has keen eyesight. He commands Gluttony to follow them from the East and at the same time, he has to catch up with Scar.
Edward tries to calm Winry from firing the gun. Scar asks her to leave if she is not shooting him, but she will be his enemy once the bullet is released from the gun. Worried that Scar might harm Winry, Edward jumps in between them. Alphonse comes in to knock Scar away to protect both Edward and Winry. While Edward tries to persuade Winry to put the gun down, Alphonse is fighting alone with Scar. Edward places her in the care of the military entrusting them to take her back to Central and safety.
Meanwhile, Colonel Mustang receives the information of the battle location and sends Riza to help them to capture the Homunculus.
Rin Yao and Ran Fan have reached to a dead end during the flee. The Fuhrer found their location and sends Gluttony to take care of Scar. Ran Fan realises that she is putting her master in a risky situation when Rin Yao refuses to leave her behind. To relieve her master's burden, she pulls a knife and cut off her senseless left arm.
Alphonse is fighting alone against Scar but saves by Edward who arrives in time. Suddenly, Gluttony appears in their fight and attacks Scar. The Elric brothers are expecting Rin Yao to take the Homunculus, but he is nowhere to be seen. Without everyone's knowledge, Rin Yao is suddenly flying up from the sewer and shoves a large explosive down Gluttony's throat. Gluttony's head explodes, and before he can regenerate, Edward transmutes a metal wire for Rin Yao to restrain Gluttony in a much-compressed state.
Following the bloodstains on the ground, the Fuhrer thought that he has located Ran Fan, but he only found Ran Fan's left arm which ties to a stray dog. Ran Fan hides in the same sewer, and the water washes away her blood to avoid being tracked by the enemy.
A disguised Riza comes to rescue Rin Yao, and they flee together with Gluttony. Scar was shot by Riza, and the Elric brothers have to pretend that they have no association with Riza in front of the soldiers. While Edward is going to finish him off, Mei Chan and Xiao Mei suddenly appear and rescue Scar.
Rin Yao tells Riza that he needs to rescue Ran Fan no matter what. As Riza and Rin Yao go careening through the streets with the captured Gluttony, they catch the attention of the Fuhrer who recognises Riza despite her disguise.
Riza's bullet went through Scar's leg. Mei Chan uses Rentanjutsu which is equivalent to the alchemy of Xing to stop the bleeding. When they plan to run further as the soldiers are getting closer, she only realises Xiao Mei is missing. Meanwhile, Alphonse found Xiao Mei and wants to keep her as a pet despite Edward's objection. At Central, the brothers go to see Winry, and it turns out that King Bradley has been keeping her company while she tells him about how she grew up with the Elric brothers.
When they return to the hotel, there is a call for Winry. Garfiel asks her to come back to Resembool as soon as possible since the shop is understaffed. In a different situation, Jean Havoc still continues to train his muscles despite the recovery chance is slim. Both he and Winry in their own ways with the support of their friends will get through the tough times ahead.
The Elric brothers send Winry off at the train station. Edward promises her that they will get their original body back and the next time he makes her cry, it will be due to tears of joy. As the train pulls away and Winry watches the brothers walk away, she realises that she is in love with Edward and probably has been for a while. Colonel Mustang picks them up from the train station. On the way to the safe house, the Colonel picks up Dr Knox to treat Ran Fan's self-amputated arm.
The Colonel introduced himself to Rin Yao and thanked him for helping Maria Ross, and Rin Yao expresses his gratitude for bringing a doctor for Ran Fan. Dr Knox is curious when he sees Gluttony at one of the rooms and they explain to him that he is a Homunculus and there's a possibility that he has a connection with the higher level in the military. During the discussion, Rin Yao points out that the highest level of the military has been corrupted and King Bradley or the Fuhrer is a Homunculus. According to the books, Homunculi cannot reproduce, but the Fuhrer has a kid. Then, Dr Knox tells them that the kid is adopted by the Fuhrer and his wife. While they are arguing who should get the Philosopher's Stone after getting the information from the Homunculus, Gluttony realises Colonel Mustang is there, and he shouts that the Colonel has killed Lust.
Suddenly, a large carved hole appears from the side of the safe house as well as an accompanying trench showing the path that the destruction took along the ground. They are shocked and confused with Gluttony who crouches on all fours at the mouth of the trench, his bonds mysteriously snapped and several writhing teeth protruding from his torso.
The Fuhrer is suddenly addressed from the shadows by the unseen Pride, who mentions that he has heard of Scar's escape from capture. But when Wrath or the Fuhrer replies that Gluttony has been captured, the shocked Pride remarks from his hiding place that the humans have been making fools of them lately. Pride promises not to report Wrath's rebellious words to Father. She asks what he will do, and Wrath responds that he knows Gluttony's location and those who captured him.
Dr Tim Marcoh sits in a small cell guarded by a pair of chimeras as Envy enters to bring him some food. Remarking that Marcoh still hasn't touched his previous meal, Envy reminds the doctor that he is an important Human Sacrifice candidate and needs to keep his strength up. Forgoing the food once more, Marcoh demands to know what the Homunculi are planning to do with him, but when Envy refuses to speak, the doctor reveals that he has already figured out a great deal on his own. As Envy mocks Marcoh's human weaknesses and inability to save millions of lives at the cost of a few hundred, Wrath enters the cell. He informs Envy that he is going to fetch the captured Gluttony from where Colonel Mustang's crew is holding him. When Envy prepares to leave, she expresses her hope that Gluttony hasn't gone out of his mind yet.
Meanwhile, Riza comes to the safe house and tries to get a closer look at the sudden patch of destruction from outside. The Colonel tells her not to provoke Gluttony as, as it seems to be only after him. While Colonel Mustang and the others desperately dodge Gluttony's cost of attacks, Rin Yao rushes inside to get Ran Fan to safety, explaining that there had been more to the Homunculus than they had surmised.
As Edward amazed with the ability of alchemy of creating such monster, the Colonel decides that their only option now is to kill Gluttony. Donning his Flame Alchemy glove against the Elrics' protests, the Colonel declares that their own survival takes top priority and they cannot afford to let the Homunculus escape this location with the knowledge of his captors' names and faces. But when he unleashes a torrent of flame on the Homunculus, the inferno is harmlessly drawn into Gluttony's mouth and swallowed by the large eye at the centre of the dark abyss, proving that this Homunculus will not be as simple to beat as the last. Terrified, the Colonel flees toward the nearby treeline with the Elric brothers as Gluttony gives chase. They split up in the forest to confuse their pursuer, but Gluttony immediately targets the Colonel. Fortunately, Riza also appears on the scene, and diverts Gluttony's aim with several head-shots from her pair of sidearms, allowing the Colonel to escape ingestion.
Back at the house, Dr Knox and Rin Yao help Ran Fan into the Colonel's car and prepare to flee the area once the others return. As Gluttony busies himself with the dummy of the Colonel transmuted by Edward, the Elrics and heavily injured Colonel Mustang (helped along by Riza) make their way back to the car. The Colonel gets in with Riza, and the Elrics demand that they leave. The Colonel is reluctant, but Edward reminds him that there are new facts regarding King Bradley's identity that the Colonel must confirm and act upon now. Despite Dr Knox and Riza's protests, Edward, Alphonse and Rin Yao opt to remain on the battlefield and try to get as much out of Gluttony as possible. They thank the adults for the help but remark that capturing a Homunculus was their plan and that they need to see it through to the end. Hearing this, Riza loads a pistol and hands it to Edward to use for protection and, though he remembers the incident with Winry and Scar in the alley, Edward gravely accepts the weapon.
In the car, the Colonel tells Riza on what Rin Yao had said about King Bradley and remarks that it could be problematic if other Homunculi are posing as humans.
Meanwhile, a black horse races in the opposite direction, toward the forest where Gluttony has gone berserk. The boys hide in the forest, fearfully listening as Gluttony screams for the death of Lust's killer. But as they flee from a fresh attack in their direction, the boys stop on cue from Rin Yao and Xiao Mei, who notice the black horse that has just appeared on the scene. The horse verbally commands Gluttony to stop rampaging and then turns to the shocked trio of boys. Apparently, recognising Rin Yao, the horse quickly morphs into Envy.
Previous volume: Fullmetal Alchemist Vol. 11 (Fullmetal Alchemist #11).
More reviews can be found on Goodreads: Fullmetal Alchemist Vol. 12 (Fullmetal Alchemist #12).