Detective Thomas Moore is a protagonist and point-of-view character in The Surgeon. He provides a point of contrast with Rizzoli. Where Rizzoli is defined by her job, Moore is largely defined by his relationships, past and present.

Moore’s primary conflict as a character is his moral responsibilities. As the derisive nickname “Saint Thomas” suggests, Moore is seen as—and makes every effort to be—morally upright. His name itself is symbolic of this desire: Sir Thomas More was a 16th-century theologian and political figure who was widely recognized for his piety and devotion to the church. Moore, similarly, is seen as an upright cop who “never stepped over the line, never swore, never lost his cool” (87). He is one of the few detectives in the department who does not discriminate against Rizzoli on the basis of her gender. However, when Moore meets the strong and beautiful Dr. Catherine Cordell, his saint-like existence is put to the test.

In a classic stereotype of fictional police detectives, Moore is haunted by a tragic event from his past. Two years ago, his wife Mary collapsed from a cerebral hemorrhage; she died after six months in a coma. At the beginning of the novel, Moore is still reeling from Mary’s death: “He still wore his wedding ring, still kept her photo on his desk” (87).

However, when he meets Cordell, he begins to fall in love again. His attraction for her is challenging to his moral framework on two fronts. He worries that his love for Cordell is a form of betrayal of his late wife. He projects this fear onto his mother-in-law Rose, “wonder[ing] whether she would forgive him if he ever remarried” (170). More seriously, it is against ethical guidelines to have a sexual or romantic relationship with a person of interest in a criminal investigation. As Rizzoli points out, the relationship causes him to “los[e] his objectivity” (131). Further, Cordell is uniquely vulnerable as a victim of sexual assault who is being targeted by a serial killer. Moore begins to see himself as “Saint Thomas the Fallen, brought down by his own desires” (294).

This conflict is resolved in classic romantic fiction fashion. After the case is over and Hoyt is arrested, Moore and Cordell get married.

Warren Hoyt is a serial killer who works as a medical laboratory technician at Interpath Labs, the largest medical laboratory in the city of Boston. He is the antagonist of the work. Throughout most of the novel, Hoyt goes unnamed and unknown by the other characters. He is referred to only as The Surgeon. His character is portrayed through first-person passages where he waxes poetic about his passion for ritual human sacrifice and his view of himself as a murderer more generally.

The source of Hoyt’s erotic fantasies about control, blood, and death are unknown. As he notes in the epilogue, “As a child I tortured no animals, set no fires […] I attended church. I was polite to my elders” (411-12). It is suggested, although not definitively stated in the text, that it was his relationship with his lab partner Andrew Capra, while in medical school at Emory University, that activated these fantasies and Hoyt’s desire to act on them. Hoyt idolized Capra and saw him as a hero for his bloody realization of their shared desires to murder and dominate women. He observed Capra’s murders and, on the night Capra attacked Cordell, finally felt ready to take part in them. He then moved to Boston when he learned Cordell was living there to get revenge on behalf of his dead partner.

Hoyt’s actions were also inspired by a combination of his understanding of mythical ritual human sacrifice and a desire to satisfy the erotic need he had to control and dominate women. Throughout his monologues, Hoyt references mythic sacrifices like King Agamemnon’s sacrifice of his daughter Iphigenia to appease the goddess Artemis and win her favor for the Trojan War. He also describes in detail human sacrifices done by the Vikings and the Aztecs in the medieval and early modern eras. Hoyt seems himself as part of this tradition in imbuing the spilling of blood with a spiritual quality. As he reflects, “the ancients considered blood a sacred substance […] and I share their fascination with it” (275). Hoyt inscribes his own pathological eroticism within this mythic narrative. When he recounts the sacrifice of Iphigenia, for instance, he wonders “how many of those soldiers [watching] felt […] their cocks harden?” (369) He sees his own and Andrew Capra’s actions as part of this lineage of ritual sacrifice. This accounts for his comments to victim Nina Peyton that she was “contaminated” and he would ritually remove her “tainted” uterus to “make [her] pure again” (200).

Hoyt is ultimately discovered by Rizzoli. Although he is shot by Cordell, he survives and is put in prison. In the next book in the Rizzoli and Isles series, Hoyt returns.