Achilles Ferrante functions as both a protagonist and an antagonist in Tierney’s life, a deeply complex character who encompasses both violence and intense love. Raised by a father who only rewarded him for acts of cruelty, Achilles learns to equate protection with absolute control. He systematically murders Tierney’s sexual partners, installs surveillance in her apartment, and monitors her every move, framing these violations as necessary acts to keep her safe. His character arc revolves around learning to transform this intense, domineering possessiveness into a form of love that still grants Tierney the freedom she craves.

The physical scars that mar Achilles’s face, sustained while saving Tierney from a fire she started, are a powerful symbol of his sacrifice and their shared, traumatic past. While his scars are frightening to some, Achilles leverages his appearance to support his identity as a stern, fear-inducing enforcer of his family’s interests. He also retains a powerful sexual allure to which Tierney cannot help responding. Achilles is heavily tattooed, which heightens his “bad boy” image and simultaneously reveals his sentimental nature: The first tattoo he ever got is based on an imprint of Tierney’s lipstick after she kissed his neck. 

Ultimately, Achilles is a dynamic character defined by his capacity for sacrifice. He willingly forfeits his lifelong ambition of becoming the head of the Ferrante family to save Tierney from a forced marriage, an act that solidifies his devotion to her above all else. His greatest test comes when he agrees to participate in Tierney’s sexual encounter with Alex Rasputin. This act of extreme self-control, which he describes as feeling “like death” (430), is the final proof that he has evolved. He demonstrates that his love is no longer about ownership but about honoring Tierney’s agency. This transformation allows him to finally earn her trust and break the toxic cycle of control and rebellion that has defined their relationship for years. Alongside this sacrifice, Achilles demonstrates his ability to love and nurture Tierney through actions such as nursing her at the cabin and stocking the fridge with her favorite snacks after they move in together. 

Achilles’s character arc appears to be complete after Tierney accepts his marriage proposal. She agrees to a vision of a quiet life together in Naples. While Achilles will continue to work for the Ferrante family, overseeing their operations in Italy, he will have a much more modest role and appears to have given up ambitions of wielding significant power. However, the news of Vello Ferrante’s death at the end of the novel unsettles this resolution, leaving space for Achilles to continue to grow as a character as he explores the possibility of assuming leadership.

Tiernan Callaghan, Tierney’s twin brother, is her fiercest protector. His character is largely static, defined by his devotion to his immediate family: his wife Lila, their son Nero, and Tierney. Having shared Tierney’s traumatic childhood in the Siberian work camp, he understands her in a way no one else can, and his primary motivation is to shield her from further harm. However, his methods are often as controlling as Achilles’s, such as when he orchestrates Tierney’s marriage to Stefano Coppola in a misguided attempt to give her a stable life away from New York.

Though a ruthless and feared figure in the Irish Mafia, Tiernan has been somewhat “domesticate[d]” by his love for Lila, showing a capacity for tenderness that he reserves exclusively for his wife. His loyalty is absolute but narrowly focused. For Tiernan, personal bonds are the only law that matters, and he is willing to burn the entire underworld down to protect those within his small circle. Tiernan does demonstrate a capacity to be flexible and thoughtful through the gradual emergence of an alliance with Achilles. Since the two men love Tierney and value her safety above everything else, they often work together to protect those shared interests (such as when they attack Vello in retaliation for his decision to hire an assassin to kill Tierney).

Luca Ferrante is Achilles’s older brother and is a primary antagonist and a foil. He is a pragmatic, ambitious, and emotionally detached mobster who represents the old-guard traditions of the Camorra. Described as having the personality of a “sodium-free rice” (27), Luca’s coldness stands in stark contrast to Achilles’s passionate, chaotic nature. His actions are driven by a hunger for power and a belief that emotion is a weakness. This is most evident in his past actions, such as when he forced Tierney to break Achilles’s heart, claiming it was an order from their father to protect the family’s interests.

As a character, Luca is largely static, remaining steadfast in his pursuit of becoming the head of the family and viewing relationships as transactional. His loveless marriage to Sofia and his indifference to her burgeoning connection with Jeremie Rasputin highlight his inability to form genuine emotional bonds. He believes he and Achilles are the same, telling him, “You can’t feel anything, just like me” (274), and is rattled to discover Achilles’s capacity for love. Luca’s character depicts the psychological cost of a life dedicated solely to power, suggesting that his emotional emptiness is its own form of damnation.

The youngest of the Ferrante brothers, Enzo is a supporting character who provides a necessary touch of humanity and comic relief amidst the bleakness of the mafia world. He is dubbed the “sunny golden retriever of the family” (28), possessing an outgoing and friendly demeanor that contrasts with his domineering and frightening brothers. Despite his cheerful facade, Enzo is grappling with a significant internal conflict regarding his closeted sexuality. He agrees to enter an arranged marriage with Katya Rasputin sacrificing his own happiness for the sake of a strategic alliance. However, the palpable tension between Enzo and Agent Tom Rothwell sets the stage for significant conflict to come. Enzo’s private struggles suggest a hidden depth and pain beneath his carefree exterior, making him a more complex figure than he first appears.