Cinder struggles to stay hidden, but when Aimery shoots civilians and tortures Maha, she rushes out with Wolf. She offers herself in exchange for the people’s safety, but Aimery kills Maha anyway. Gunfire erupts, Wolf attacks, and chaos spreads through the square. Cinder and Wolf manage to kill two thaumaturges and two guards, and they injure Aimery before guards and manipulated citizens overpower Cinder and Wolf and force them to their knees.

Scarlet and Thorne shoot at Aimery and the thaumaturges from a factory window, then escape while guards search the building. Thorne, still wearing a guard uniform, pretends to capture Scarlet so they can get away. Scarlet wants to keep fighting, but she realizes she cannot save Cinder and Wolf. Meanwhile, Iko searches Maha’s house for Winter and finds guards and a thaumaturge instead. When Iko tries to incapacitate the thaumaturge, a guard named Kinney points a gun at her. Iko uses the thaumaturge as a shield, and Kinney accidentally shoots and kills the thaumaturge. He shoots Iko and is horrified to realize she is an android. Another guard, Jerrico, attacks Iko, but Winter comes out of hiding and fights him. Kinney is shocked to see that Winter is alive, and Jerrico reveals that the queen ordered her death. After Jerrico injures Winter, Kinney kills him, frees Iko, and tells her to get Winter somewhere safe.

Guards take Cinder and Wolf to an underground cargo port. Kinney claims that an android killed the thaumaturge and Jerrico before he destroyed it, so Cinder believes Iko is dead. Aimery forces Wolf to kneel and obey him against Wolf’s will. He orders the guards to kill Cinder, then changes his mind, deciding that Levana should dictate Cinder and Wolf’s punishments. After they return to Artemisia, the guards separate Wolf from Cinder. They take Cinder underground and lock her in a prison cell with Adri and Pearl.

Winter dreams of meeting with Levana, who berates her, telling her that she does not deserve the kindness others show her. Winter wakes in Maha’s house with Scarlet, Iko, and Thorne, who tell her that guards captured Cinder and Wolf and killed Maha. Winter shares that Levana will publicly execute Cinder in Artemisia and likely broadcast it. The group fears that Cinder’s execution will happen at the wedding. Thorne insists they stick with the plan to rescue their friends and overthrow Levana. Winter proposes a new plan. She sends Thorne and Iko back toward Artemisia while she and Scarlet go underground into the lava tubes to seek support from Levana’s mutant soldiers.

Cress waits in Jacin’s room while he prepares for a long shift at the wedding. Another guard, Kinney, arrives and finds the pair. Jacin pulls a gun on him, but Kinney reveals that he saved Winter’s life and warns that Levana may soon trace the royal podship back to Jacin. He explains that he killed Jerrico when Jerrico tried to kill Winter. Kinney tells Jacin that he owes Winter a debt for saving his sister’s life. After Kinney leaves, Jacin decides that he and Cress must escape that night.

Kai meets with Torin before the wedding and complains about being trapped and cut off from news. Torin shares that the Lunars found Thorne’s ship and plan to search it. A servant then delivers a wedding gift from Levana. Inside the box, Kai finds one of Cinder’s cyborg fingers and realizes that Levana captured her. Elsewhere, Levana prepares for the wedding while Aimery reports that Jacin abetted Winter’s escape then disappeared. Levana decides that Winter can remain “dead” if people believe it. She orders Jacin’s parents to be executed for Jacin’s treason.

Kai dresses for the wedding in a daze, still hoping Cinder may be alive. Torin reminds him that he can still stop the war and gain the antidote by marrying Levana, but Kai feels trapped. Guards escort him to the grand ballroom, where hundreds of guests wait. When Levana enters in a red wedding gown, Kai finally accepts that no one is coming to stop the marriage. The ceremony begins.

Kai mechanically goes through the wedding ceremony while Prime Minister Kamin leads the vows. When the ceremony nears completion, Kai grabs the scissors from the altar and tries to stab Levana. She uses her glamour to change her appearance to mimic Cinder’s and her manipulation stops his hand, but the scissors cut her arm. Under pressure, Kai finishes the ceremony, and the marriage becomes official. When he kisses Levana, he tells her that Selene is more beautiful than she is.

Cress and Jacin sneak through tunnels beneath Artemisia, trying to escape before Levana discovers the truth about Winter. They reach a cargo platform where guards inspect trains. A fight breaks out, and Cress spots Iko and Thorne. Jacin joins the fight, and together they subdue all the guards. Thorne punches Jacin for his betrayal, then hugs him for protecting Cress. Aimery appears on a broadcast and announces that Levana and Kai are married and that a special trial will air in 20 minutes.

Cinder chips away at the prison wall with one of her built-in tools, even though she knows she cannot escape in time. She argues with Adri and Pearl after Pearl asks why the guards called her a princess. Adri reveals that Garan may have known Cinder’s identity and accuses Cinder of cruelty, including for her failure to save Peony. Cinder rejects Adri’s approval for good. Guards arrive, and Aimery tells her that Levana wants her at the wedding feast. Adri and Pearl are also brought along.

Cinder enters the feast hall and sees Levana, Kai, nobles, guards, and wolf soldiers waiting around the throne. Levana announces that Cinder’s trial will serve both to entertain and to warn Lunar citizens. Aimery puts Adri on trial and accuses her of helping Cinder and hiding the designs for Garan’s weapon, which neutralizes the Lunar gift. Kai objects, but Levana ignores him. Instead of killing Adri, Levana offers her mercy if she disowns Cinder and swears loyalty to the queen. Adri agrees, and Levana turns to Cinder’s trial.

Aimery lists Cinder’s crimes, but Levana interrupts and considers various cruel methods of execution, eventually settling on having Adri dismember her. Cinder realizes that her cyborg vision can see through Levana’s glamour more clearly. She cedes the human part of her brain to the cyborg part and records Levana’s true face. She declares that she is Princess Selene. When Levana orders her killed, her anger breaks her control over the guards for a moment. Cinder seizes control of them, frees herself, and starts a violent fight inside the throne room. She uses her gift to force the Earthens to take cover, before having the guards open fire. She kills the thaumaturges and nearly gets a clear shot at Levana, but reinforcements arrive. Cinder leaps from the balcony into the lake.

After Cinder escapes into the lake, chaos fills the throne room. Kai checks on the other Earthen leaders and searches the water for any sign of her. Aimery reports riots in several sectors, and civilians march towards Artemisia. In a rage, Levana orders the tunnels and ports sealed. When Europe’s prime minister demands to leave, Levana nearly attacks him, but Kai reminds her that she still needs Earth’s cooperation. Levana storms away, and Adri begs Kai to send her and Pearl home, but he tells her that no one can leave.

Cinder hits the freezing lake, and her systems begin to shut down. Her electronics and prosthetics stop responding, but she fights her way back to the surface and tries to swim away from the palace. She reaches the glass wall at the edge of Artemisia’s dome but is too weak to keep herself afloat. She starts to sink again, her prosthetics weighing her down. Someone grabs her and pulls her up. Exhausted, she realizes that Thorne is carrying her.

Cress and Iko wait on the shore while Thorne and Jacin dive after Cinder. They take Cinder to a boathouse, where Jacin revives her. Cinder wakes weak and injured, and the others realize the water damaged the connection between her brain and her prosthetics. They hide in a mansion belonging to absent court members. In the kitchen, Cinder explains which of her systems failed. Iko suggests that she may be able to repair Cinder if they find the right parts and tools and reminds her that she can be fixed, despite the damage. Iko recommends that everyone rest.

Winter and Scarlet travel through Luna’s lava tubes in search of wolf soldiers. Scarlet worries that they are lost, but Winter remains certain they will find the soldiers and win them over. Winter explains that the barracks and training grounds are somewhere in the lava tubes. Scarlet warns that the soldiers are monsters, but Winter insists that they are still men who may choose freedom. Winter compares the soldiers to Wolf, who remains a steadfast ally despite having been partially transformed into a Wolf soldier, but Scarlet insists that Wolf is nothing like the soldiers. Eventually, both girls smell the soldiers.

Winter and Scarlet find the barracks for Regiment 117 of mutant soldiers. Winter uses her biometric credentials to enter the cavern, alerting Levana to their location. Inside, they find a regiment of about 100 soldiers in a huge cavern. The men stop what they are doing and focus on the girls.

The soldiers close in on Winter and Scarlet, mocking and threatening them. Scarlet asks to speak to the strongest alpha of the 11 in the regiment. The soldiers notice that Scarlet smells like an alpha, and she admits her relationship with Wolf. Alpha Strom steps forward to speak for the pack. Winter tells them that Levana uses them as tools. Instead, they should help Cinder’s rebellion and fight for their freedom. The soldiers surround Winter and Scarlet, continuing to taunt them.

The soldiers attack and restrain the girls. Winter starts hallucinating and muttering, and the soldiers recognize it as Lunar sickness. Scarlet explains that Winter refuses to use her gift because she does not want to control others. Thaumaturges arrive and order the soldiers to kill the girls. Instead, the soldiers turn on the thaumaturges and kill them. Afterward, Winter again asks for them to join the rebellion. Alpha Strom agrees if Winter swears never to control them.

Scarlet sets strict terms for the alliance with the mutant soldiers. She tells Alpha Strom and the other alphas that they may attack only Levana and those who serve her, not civilians. The alphas agree. They climb out of the lava tubes into the lumber sector of LW-12 and find civilians training. People panic at the sight of the soldiers, but Scarlet introduces Winter and explains that the soldiers joined their cause. The local leader says Maha Kesley’s death inspired others to rebel. Alpha Strom helps train the civilians.

Levana listens as Aimery reports unrest in more sectors, noting blocked trains, stolen supplies, and killed guards. Another thaumaturge shares the news that Regiment 117 has joined the rebellion, killing 8 thaumaturges and allying with Winter. Security feeds show Winter and the soldiers moving into LW-12. Aimery offers to kill Winter, but Levana refuses. She decides to punish the outer sectors by cutting off food and supplies until the people beg for forgiveness, and she says that she will deal with Winter herself.