Kaine flies Helena back to a location near Resistance headquarters on Amaris. There, Helena meets with Crowther. He threatens to bar her from headquarters if she doesn’t continue liaising with Kaine on their behalf. Ivy bursts into the room wanting to know what happened to Sofia Purnell, revealing that they are sisters. Ivy admits that she was the one who knew the location of the prison and shared it with Sofia. Crowther points out that because of this, it is Ivy’s fault that Sofia dies, and she leaves with an angry look. 

Crowther tasks her with returning to the prison to speak with the prisoner they found with Luc, called Wagner, about how Morrough and the Undying are using their prisoners. Together, they determine that Morrough is indeed using the Undying to garner more power. Wagner confirms Kaine’s description of how Morrough uses his bones to hold the Undying souls and power, and he sketches out an array that allows Morrough to pull this power from them. Much later, long after they leave, Wagner is found dead, clearly by Ivy’s hand, and she threatens Crowther next.

Later, Helena learns from an orderly named Penny that Lila has to go before the Council “for compromising Luc’s safety” (687). They cannot punish Luc for circumstances leading to his capture, so they are using Lila as a scapegoat. She also questions Helena about her use of necromancy with Soren.

Over the following days, Helena tries to heal Lila so her resonance returns, but she is not successful. A discouraged Helena misses Kaine.

Days later, Helena and Kaine reunite. During a passionate embrace, Kaine notices that Helena is upset. She expresses her sadness and frustration with life at headquarters, begging Kaine to run away with her. Kaine opens up to Helena, sharing stories from his childhood. They decide they can’t run away but promise to call each other using their rings if they ever need each other.

Kaine starts calling Helena more often. Each time, they have a passionate encounter. Kaine promises to care for Helena, but she can’t help feeling guilty for using him all this time. He says that if she wants to run away, he will help her escape, but she says no. Helena opens up about her guilt regarding the torture she was forced to perform. Kaine opens up more about losing his mother. The lovers again swear to care for each other. As they talk more about Morrough, they realize that the best way to kill him is to siphon off his power by killing the Undying. As she leaves, he tells her to use the ring if she needs him, and he will come.

Helena and Kaine continue to meet frequently, with Amaris arriving to take Helena to whatever hiding place Kaine has found for them. At headquarters, Helena finds out that Luc has requested that she not be let near him or Lila. She works in the lab with Shiseo on nullium cuffs that will suppress alchemists’ resonance. Kaine calls for her whenever he is injured, and she heals him, knowing that he is being tortured because of the secret work he is doing for the Resistance, which he is really doing for her.

In the spring, the Undying attack the Resistance with a nullium bomb. Although the hospital was prepared for such an attack, they struggle to maintain their strength. Picking the shrapnel out of the survivors is frustrating and delicate work. Luc, however, seems to regain his power after the attack and takes control in a new way, seeming to take control of his leadership for the first time. Lila is still officially Luc’s paladin, but she isn’t taking part in combat. 

Helena works tirelessly at the hospital. When she’s off, she lies in bed, twisting Kaine’s ring and musing on their relationship and Morrough’s plans. She is still disturbed that he can trap his victims’ souls in their bones and use the bones to strengthen himself, and she ponders the sketch that Wagner gave her of Morrough’s array. She reflects on when Soren died and she had performed necromancy on him, how part of his energy stayed with her. She begins to experiment with using her resonance to capture patients’ vitality as they die, and she finds that she can capture it in obsidian shards.

One day, Lila tells Helena she is pregnant with Luc’s child. Helena fears for Lila but understands that the baby could change her and Luc’s story. Helena promises to support her, and they decide they have to tell Crowther. She hasn’t told Luc yet.

Helena disguises Lila’s pregnancy, reporting that she has bog cough, an illness requiring quarantine. She forbids Luc to see her, but Pace soon determines what’s going on and advises Helena on the pregnancy.

The war continues, swinging between both sides, and as Luc assumes leadership, Ilva seems to get weaker; Helena realizes how old the other woman is. One day, the Resistance finds Resistance prisoners in one of Morrough’s holdings; they are kept in tanks, and Helena interrogates Warden Mandl, who they captured, to find out why. She uses her animancy skills to access Mandl’s mind and memories, and she is horrified to discover that the fighters were being kept alive to serve as potential bodies for the Undying, test subjects, or necrothralls.

Helena meets with Kaine, and they discuss her recent encounters with obsidian. They decide to study it to test its effects on the Undying.

The Resistance weakens, and the hospital remains full. One day, Helena is taken out of the hospital to a field hospital, despite the fact that Crowther was keeping her at headquarters to keep her safe, as per the terms of his agreement with Kaine. When the Undying attack the field hospital with a nullium bomb, Helena takes charge and decides to evacuate. As they flee, another blast goes off.

Helena wakes up injured, a piece of metal lodged in her chest. She fears she’ll die without seeing Kaine again. She loses consciousness. When she wakes up, she finds herself in a hospital-like room with Kaine standing over her. Kaine reminds her how important her survival is to the Resistance, because if she dies he swears to kill all of them. He tells her they are at his family’s estate, Sprirefell. Then he brings a necrothrall in to care for her, his childhood nurse, Davies. Kaine reanimated her body after her death and promises Helena she’ll care for her in his absence. Kaine returns periodically to keep her updated, and he tells her that the Resistance is starting to lose the war again.

Over the following weeks, Helena slowly recovers in Kaine and Davies’s care at Spirefell. Kaine meanwhile reveals more news from the war. He posits that Morrough kept Luc alive when he captured him because he was trying to extract his soul and empower himself. It is a month before she recovers.

When Helena regains her strength, she and Kaine have sex. She realizes she loves him but doesn’t say so aloud. One day, he tells her that Ilva and Althorne have died, and Lila believes that Helena is dead and is “inconsolable.”

Afterwards, she returns to headquarters. She learns from Pace that Lila is stable. Then she meets with Crowther, and they discuss the uses of obsidian. Helena then demands a deal with Crowther: She insists on approving all his orders to Kaine in exchange for her continued cooperation. Crowther reluctantly agrees.

Helena recovers the obsidian talisman, and the Resistance begins trying to manufacture obsidian weapons. She meets with Kaine and explains that the obsidian can kill the Undying.

As the weeks pass, Helena feels different. She continues working with Crowther but refuses to torture anyone else. One day, she meets with Rhea Bayard, Titus, and Luc, and tells them she might have found a way to cure Titus. An angryLuc dismisses her suggestions. The friends get into an argument. Frustrated with Helena, Luc pulls away before they resolve the disagreement.

Two weeks later, Kaine calls Helena. Helena explains the deal she made with Crowther in an attempt to stop overtaxing Kaine. Kaine is upset because he fears Helena is in danger. They make amends and kiss, swearing their loyalty to each other.

Word spreads that Hevgoss has allied with the Undying. Luc and the Council prepare defensive tactics. They try without success to gain the support of another country, Novis. They also plan to make an obsidian bomb. Helena soon shares this information with Kaine. He agrees to help by planting the bomb.

One night, Kaine finds her in the lab. Tired and overworked, she begs him to run away with her. He can’t leave yet but kisses her and promises to protect her.

After the bomb is ready, Shiseo delivers it to Kaine. Meanwhile, Helena visits Lila, and they discuss Luc and motherhood. Helena sees Elain outside Luc’s quarters; she is now his only healer, but Helena notes that the medicines she has with her don’t make sense.

Helena waits in panic to hear whether the bomb worked and if Kaine got away without being discovered. Meanwhile, Helena talks with Pace about Morrough and Luc’s capture. Helena feels suddenly afraid for Luc and goes in search of him. She hears that the bomb successfully detonated, and the Resistance becomes optimistic, but then news arrives that the Undying have taken headquarters, the Tower.

Helena finally gets an audience with Luc. He is acting just as strangely as he was in their last encounter. She realizes he is not himself, and then Luc announces that he is in fact Morrough, and says that his real, ancient name is Cetus, and he was Orion’s brother, the necromancer Orion fought in the Necromancy War. Helena realizes Morrough is controlling Luc and used him to get into headquarters. A fight ensues. Helena battles tirelessly, desperate to save the real Luc from Morrough’s control. Luc momentarily resurfaces, telling Helena to kill him in order to stop Morrough. Helena refuses and tries to save him, but he stabs himself. Luc slumps against the wall. Before dying, he makes Helena promise she’ll care for Lila and the baby.

Kaine finds Helena and saves her from the Undying, who are starting to take over. He tells her that the war is over, and the Undying have won. Helena tells Kaine everything that happened. She is devastated by Luc’s death, blaming herself for failing to recognize that Morrough had stolen his vitality long ago. He was so depleted, she couldn’t save him. She also fears that Lila is gone, and Kaine leaves to rescue her; they make a deal that if he saves Lila, Helena will escape. When he returns, she tries to break her promise, but he sedates her. When she wakes, she asks him to bring Shiseo to her with a list of items. After he leaves, Helena begins concocting an escape plan.. She will bomb West Port Lab to form a distraction so she and Lila can escape without notice. When Kaine arrives with Shiseo, he promises to support Helena.

Helena goes to where the Resistance has relocated, and she runs into Crowther and Ivy. Ivy confesses that she told the Undying how to take over the Tower because Morrough promised her that he would give her Sofia, who is now a necrothrall. Helena realizes that Crowther is dead, and he is now Ivy’s necrothrall.

Helena bombs the facility, using necrothralls. Exhausted after fleeing the site, she tells herself to survive for Kaine. On her way to safety, she encounters Lancaster, now Undying, and his followers. 

She is captured and taken to the Tower, now the Undyings’ headquarters. She is imprisoned with the other Resistance fighters, and they are forced to watch as their leaders, now necrothralls, kill other prisoners. When Morrough appears, she’s shocked to see Luc with him. She can’t reconcile what she’s seeing, as look appears to beg Morrough to become one of the Undying before Morrough kills him. 

Mandl appears and pulls Helena out of her cage. She takes Helena to where they are putting the prisoners in stasis to be used later. Mandle puts Helena into stasis without sedating her, meaning she continues to be conscious even as she is put in the tank. As she waits for Kaine to rescue her from stasis, she begins trying to rewrite her memory so that no one can find what she knows.