Rowena has gathered three witches in a warehouse. She proposes that they join her in forming the "MEGA" coven, but the witches are skeptical. They say Rowena is just looking for protection from Crowley and the Winchesters, and they are unimpressed with her skill level. In an effort to impress them, Rowena tells them that she has killed Crowley, but one of the witches tells her that Crowley is alive and still making deals. Rowena, incensed by their rejection and by the news that Crowley is still alive, kills all three witches.
At the Men of Letters' (MOL) bunker, Dean is distracted and preoccupied by memories of his meeting with Amara, while Sam has been looking into leads that might help them find Amara. Dean suggests that they might have some time, because the Amara he met was an adult, so the child Amara still has to grow up. Castiel reminds Dean that the Darkness has nearly infinite power, so "growing up" may not apply in her case. They discuss the fact that God beat the Darkness before, but doesn't seem to be around this time. Sam has hope that God may be around, but Dean and Cas do not. They also decide that Metatron may know something about battling the Darkness, so they start trying to find him.
Castiel is chained to a chair in the MOL library, because the Winchesters don't know what the attack-dog spell might cause him to do. The Winchesters have a blanket wrapped around him, because he seems to be ill and is having chills.
They discuss the fact that the spell seems to be "digging deeper", and Castiel's condition seems to be getting worse; although a human would be dead already. The Winchesters have been looking unsuccessfully for Rowena, but continue to try. Dean calls Crowley (apparently he's made repeated attempts to call him), thinking Crowley probably has demons looking for Rowena, so he may know where she is. Castiel doubts Crowley will want to help save him.
Meanwhile, at Crowley's lair, we learn that Crowley's assassins have found Rowena. He gives them permission to kill her. We also see that the child Amara is at Crowley's lair. Under the supervision of a demon-nanny, Amara has been watching videotapes of Hitler's Nuremberg speeches. Amara briefly mentions to Crowley how God tricked her and sealed her away. Crowley tells Amara that he wants her to be happy and will keep her safe from God. When he asks how God tricked her and imprisoned her before, Amara refuses to answer.
At a restaurant, Rowena has gathered two witches and is once again trying to convince them to join her Mega-coven. When the witches learn that she has the Book of the Damned, they are interested. As they are talking, a demon-possessed waiter kills one witch and tries to kill Rowena and the other witch. The second witch runs away, and Rowena utters a spell that allows her to escape, blocking her way with furniture that she moves telepathically.
Back at the bunker, Castiel has what appears to be a violent seizure. Sam and Dean decide that finding Rowena and convincing her to remove the spell from Castiel are urgently important (temporarily more important than finding Metatron or the Darkness). Castiel also tells Sam and Dean that he can hear the angels talking on angel radio, and that the angels are looking for him and for Metatron. They decide that they need to find Metatron before the angels do, but finding Rowena is still more important. Sam reads a news report about an attack at a restaurant in Denver (Cafe Elta) and the brothers decide that it could be Rowena. The Winchesters head to Denver. Posing initially as FBI agents, they question the witch that survived the restaurant attack. They quickly let on that they know she is a witch, and they convince her that Crowley's assassins are after anyone who might be connected to Rowena, including her, so she uses her scrying powers to help them find Rowena.
Meanwhile, at a bar, an angel and demon accidentally encounter one another. They decide not to fight, but instead start talking. Over drinks, they decide that heaven and hell are both being mismanaged and that they - the grunts on either side -- are getting a bad deal. They decide that it's up to the "little guy" to do something about the situation.
Back at Crowley's lair, the child Amara is in her room alone. Amara (as an adult) appears to the child Amara in a mirror and tells her that God locked them away because of his own ego.
Amara tells her younger self to remain fixed on their purpose. She also tells young-Amara that her true destiny will become clear when she gets older and becomes stronger, and that she is mightier than God is. Later, Crowley offers gifts to Amara -- a new (but blood-stained) dress and a children's book. Amara shows him that she has been reading Dante's Inferno. They have a brief discussion during which Amara says she has plans for making the world work better than it has worked under God's control. When Crowley asks for details, Amara says she's hungry. When the nanny offers her a platter of pastries, she chooses instead to eat the nanny's soul.
Later, we see that Crowley has continued allowing Amara to eat all the demon souls she wants, and that he has been feeding her only dead demon-possessed meat suits, to avoid having demented, soulless people in his lair. Crowley and Amara discuss how God's creation has led to a world where people suffer and their souls are empty. Crowley says to Amara that they, together, can make a world that is completely evil. When Amara asks if that's really what Cowley would want, he admits that tempting humanity and encouraging people to turn toward evil is rewarding. Amara suggests that good, evil, heaven and hell are unimportant and that Crowley is not seeing the big picture. When he asks for details, she refuses to answer and says "I'm hungry". Crowley feeds her another demon soul.
Later, Crowley assigns a new demon to be Amara's nanny, and instructs him to be less 'generous' with Amara's meals. Crowley is concerned that Amara is growing quickly and may get out of hand as her power grows. Later, Amara eats her new nanny's soul, too. When Crowley finds her in her room, she is already several years older. Crowley says he wants to talk to her, but she is belligerent and says that she's hungry.
Elsewhere, we see Rowena wearing a blonde wig and preparing to leave what looks like a tenement building. She approaches her taxi, only to discover that Dean Winchester is the taxi driver. She uses her powers to pin Dean to a wall and prepares to injure him further when Sam surprises her by slipping shackles on her wrists.
Back at the bunker, Castiel is using Dean's computer to search for his car (and therefore, Metatron), when he accidentally stumbles into a pornography site and starts having flashbacks to when he received the attack dog spell, perhaps indicating that the spell is having more control over him. Meanwhile, Sam and Dean have Rowena shackled in the bunker's dungeon. They search her luggage and find the codex, but not the Book of the Damned. She refuses to tell them where it is. When Sam leaves the room to go get Castiel so Rowena can cure him, Rowena reminds Dean that their deal was they'd let her go if she cured Castiel. Dean says they also want the Book, but Rowena refuses. When Dean threatens to call Crowley, Rowena challenges him to do it, noting that if she dies, they still don't have the Book, and Castiel will die. Suddenly, Sam returns, saying that Cas has left the bunker.
In the Impala, Dean, Sam and Rowena are looking for Castiel. Sam is using the GPS on Castiel's phone to locate him. As they are driving, Rowena taunts the Boys. She lets it slip that Winchesters are unable to hold up their end of the bargain when they make deals, referring to the deal Sam made with her to kill Crowley in exchange for removing the Mark of Cain from Dean's arm. Put on the spot, Sam tells Dean that he was going to tell him about that deal, but when his attempt to kill Crowley failed, he didn't see the point. Dean is annoyed that Sam kept such a secret, and Rowena seems amused that she has caused friction between the brothers. As they are talking, they get a fix on Castiel's position.
Castiel, now under the influence of the attack-dog spell, is in an alley. He finds and stalks a young woman and is strangling her to death when Dean finds them in what appears to be a storage room. Dean convinces Castiel to release the girl, but the spell takes Castiel over and he attacks Dean.
Castiel has Dean on his knees and is beating him when Sam and Rowena appear. Sam has Rowena at gunpoint (using a gun that is loaded with witch-killing bullets) and forces her to remove the spell. As Rowena recites the incantation, Castiel falls over and convulses briefly before returning to normal. He seems dazed, but recognizes Dean as Dean helps him up. As soon as Castiel is cured, Rowena utters a spell that forces Sam's gun to fly out of his hand; then she uses her powers to launch Sam across the room. When Dean sees what is happening, he rushes at her, but she uses an incantation to slam the gate shut before he can get to her. Rowena walks away.
Back at the bunker, Dean is holding an ice pack over his face, which is badly swollen and bruised from Castiel's beating. Castiel feels guilty about hurting Dean, but Dean tells Cas that there's no need for him to apologize, because he was under a spell. Castiel also feels guilty that Rowena is in the wind again, but Sam says that at least they have the codex and that if they'd killed Rowena, the Book of the Damned would be lost. Castiel sees that Dean is in obvious pain and wants to heal him, but Dean refuses, saying that he had it coming (referring to the beating Dean gave Cas when he was under the influence of the Mark of Cain in "The Prisoner").