Jeremie leaves and Achilles, Luca, and Enzo discuss a recent attack from the Coppola family. They agree to go to Naples to eliminate them. Achilles volunteers to move there with Tierney to manage the new territory. He then presents Jeremie’s suggestion to act as Sofia’s bodyguard. Luca readily agrees. As they finalize the details of the deal (making Jeremie Sofia’s bodyguard will give them access to weapons and territory formerly held by the Bratva), Achilles texts with Tierney. After the deal is concluded, Luca coldly tells his brothers that he doesn’t believe anything is happening between his wife and Jeremie, and that the deal will solidify his hold on power.

Achilles takes Tierney to the woods and shows her the remains of the men who abused her, explaining he hunted them down and killed them. Overwhelmed, Tierney cries with a mix of gratitude and anguish. Tierney participates in burning the remaining evidence of their bodies. Afterward, Achilles drives her to the office of a well-respected trauma therapist. Tierney is initially furious, but her anger subsides when Achilles reveals he has also started therapy. Achilles tells her he must go to Naples and Tierney expresses her gratitude that he is honest with her. She admits that she only feels whole when she is with him.

While settling into Achilles’s Manhattan apartment, Tierney is visited by FBI agent Tom Rothwell. Rothwell has been trying to get her to meet with him ever since she returned to New York: He still wants her to follow through on the proposal to give him information about the Ferrante family and their criminal activities. However, given her new bond with Achilles, Tierney no longer has any intention of betraying him. She claims she no longer remembers anything incriminating. Rothwell, unconvinced, warns her not to deceive him and makes a veiled threat before he leaves.

As Achilles prepares to depart for Naples, he has misgivings about leaving Tierney. She has declined security and he forces himself to accept that she can take care of herself if necessary. She makes him promise to return safely and he reveals that she has been the sole heir in his will for the last 10 years. After they share a passionate kiss, Achilles tells Tierney he loves her before boarding the jet with his brothers. She does not say it back but kisses him deeply.

Aboard the jet, Luca learns (via their networks of tracking and spies) that Stefano Coppola is in New York (not Italy). The plane immediately turns around but it will take some time to land back in New York. Panicked that Tierney is in danger, Achilles desperately tries to call her, but she doesn’t answer. Achilles orders Luca to send men to the apartment. Tierney finally calls back, and Achilles warns her that Coppola is approaching. Since she is not at home, he orders her to drive to Tiernan’s house for safety, and she agrees.

Tierney ignores the promise she made to Achilles and drives toward their newly shared apartment, intending to kill Stefano Coppola herself. She arms herself with a gun from Achilles’s hidden stash just before Coppola and his men arrive, having somehow bypassed the building’s security. Tierney hides in a secret passage in the office. When one of the men approaches her hiding place, she shoots and kills him. She takes the dead man’s bulletproof vest and then methodically kills two more of Coppola’s soldiers. However, Coppola grabs her from behind and holds her at gunpoint.

Stefano Coppola ties Tierney to a kitchen stool. Just as he finishes, Achilles bursts in with a shotgun, and a tense standoff begins. As Achilles verbally spars with Coppola to distract him, Tierney carefully maneuvers her zip-tied hands from behind her back to her front. She lunges at Coppola and attempts to strangle him. Coppola fires his gun at her, but her bulletproof vest protects her. Achilles takes advantage of these events and breaks Coppola’s neck.

With Coppola incapacitated and moments from death, Achilles rushes to confirm that Tierney is unharmed. They have sex on the floor, forcing Coppola to watch in his final moments. After Coppola is dead, Achilles rebukes Tierney for disobeying him. She explains she did it to prove that she cares for him. She finally admits that she loves him and Achilles is delighted with their increasing openness and vulnerability. Their growing emotional intimacy makes him even more determined to marry her.

After a therapy session, Tierney makes an elaborate home-cooked meal for Achilles. When Achilles arrives home, he is so stunned and emotionally overwhelmed by the gesture that he retreats to the bedroom, and Tierney later suspects that he has been weeping. Realizing that no one has likely ever cared for him in this way, Tierney kisses him passionately and silently vows to continue taking care of him. Achilles promises he will do anything to make her happy and keep her with him.

Tierney has lunch with Lila and Sofia. The women discuss their relationships, and Sofia asks what it feels like to be in love. Lila describes it as feeling secure, a feeling Sofia admits she does not have with Luca. Sofia remains oblivious to Jeremie’s obvious affection for her, dismissing his behavior. When the men join them, the contrast in the relationships is stark: Tiernan and Achilles are affectionate with their partners, while Luca is cold and dismissive toward Sofia. Disturbed by his cruelty, Tierney tells Achilles and Enzo they need to do something about their brother.