Opening in the old Rankless District with Lyta-Zod and Seg-El, they banter together and eventually Seg arranges for them both to move to Kryptonopolis with her mother's blessing, who provides them with a house and restores Seg's rank as a member of House El. He asks Lyta to bind with him, and although she agrees and all seems well, the entire idyl is only an illusion, created by the Black Mercy. The real Seg-El tries in vain to locate Brainiac from the Fortress of Solitude, but Nyssa-Vex dissuades him and asks to seek out Val-El until she is interrupted by Jayna-Zod and Dev-Em's arrival.
In Kandor, Lis-Ser tries and fails to gain somatic control of Doomsday, disappointing General Zod. Zod walks with Lis-Ser and discovers her concern over Brainiac's ship suddenly vanishing, reassuring her that if they can control Doomsday, they can defend themselves from Brainiac. Lis-Ser protests that Doomsday is immune to every psychoactive drug on Krypton, so Zod allows her to use one not native to Krypton; the Black Mercy toxin. Taking Lis-Ser into a secure room, he reveals the Black Mercy attached to Lyta-Zod, feeding on her. In her hallucination, Lyta-Zod prepares for her binding with Seg, her mother for once totally supportive of her choice to be with Seg. Lyta is overwhelmed with gratitude toward her mother, saying that she is happy.
Back in the Fortress of Solitude, Jayna and Dev inform Seg that Zod's fleet is now complete and planning to launch toward Wegthor. They then plan to break into Fort Rozz in order to halt the launch, using smuggler's tunnels Kem and Seg used to use. They execute the plan, but Seg and Nyssa are quickly captured, leaving Jayna and Dev to retreat.
Extracting the toxin from the Black Mercy, Zod explains that Lyta-Zod has hosted the Black Mercy for months after becoming "troubled" by Seg-El's loss, that Zod implanted her with it because it gave her "peace" in a way he could not. He further explains how he then cloned Lyta, somatically reconditioned said clone to be loyal, and was nonetheless distraught when the clone was killed by Jax-Ur. Lis-Ser grows concerned, as the Black Mercy reacts negatively to the process of extraction and further agitation may collapse Lyta's hallucination. Zod however insists she proceed as they require more toxin, saying that Lyta's strength "has been tested before. So it must be again."
Within Lyta's hallucination, reality begins to break down and become inconsistent. The blissful dream first shows cracks when, after binding with Seg, the Oracle predicts that their child will "conquer 467 planets and eradicate 233 billion alien life forms", causing Lyta to be horrified while everyone else still seems oddly happy. She tries to reason with the priestess of Rao, but she departs and everyone continues celebrating. She seeks comfort from Dev, who instead accuses of her of not loving him, before walking away angrily and looking back with his arm suddenly blasted off.
Lyta then bumps into an illusory Nyssa, who scolds Lyta further, causing her to panic and flee the room. An illusion of Seg arrives initially offering comfort, but then turns accusatory, saying she betrayed them all, and a facsimile of Jayna-Zod suddenly starts bleeding. Lyta asks why, and Jayna says "because you shot me". Lyta flees again, in denial.
Meanwhile, Lis-Ser has successfully completed the extraction of the toxin and is fascinated by it. General Zod notes that in his travels, the only way he saw to escape the Black Mercy was to reject the illusion it creates, but few have the awareness to detect the illusion and fewer still have the will to relinquish it. When Lis-Ser becomes concerned for Lyta, General Zod threatens Lis-Ser over what will happen if she fails to deliver him Doomsday, and she resumes working.
Lis-Ser then administers a dosage of the toxin that would keep Doomsday pliable without actually sending him into an illusion, which succeeds, but more toxin is required. Lis-Ser extracts more, and Zod leaves to deal with the captured Seg-El and Nyssa-Vex. After Lis-Ser leaves, Lyta then awakens from her hallucination, ripping the Black Mercy off of her face. A guard quickly enters, but Lyta grapples with and shoots him, fleeing and leaving him dead behind her.
Meanwhile Seg, coming before Zod, accuses him of letting Lyta die. Zod fires back that Val-El blew up the Space Elevator base station, and yet Seg does not demonize him. Zod then orders Nyssa to be somatically reconditioned as he believes Seg to be immune to it, and detains them until he can oversee the process.
Back with Jayna and Dev, they are accosted by two Sagitari soldiers, until Lyta arrives and kills them. Together they flee to a secure room where Dev pulls a gun on Lyta, demanding to know who she is, as he saw another "Lyta" (her clone) die. Lyta explains how she broke free of the hallucination after realizing it was not real, and how she came to be in that situation; General Zod attacked her when she refused to obey him.
Jayna then tells Lyta that Seg has escaped from the Phantom Zone and is in Fort Rozz, in danger, so although Jayna suggests taking Lyta to safety first, Lyta insists on rescuing them immediately. Seg meanwhile fruitlessly searches for a way out of his cell in the detention center until Dev arrives and uses his robotic arm to break them out. Lyta and Jayna then create a fake distress signal within the shipyard, diverting forces there and allowing Nyssa, Seg, and Dev to escape to meet up with Jayna and Lyta. Seg and Lyta are overjoyed to be reunited once more.
Finally, General Zod rushes to Lyta's room only to discover her gone, and in his anger orders the Sagitari to prepare to launch for Wegthor to destroy every soul there.