Necessary Monsters: The Defining Motif of Killers of a Certain Age

What Are the "Necessary Monsters"?

In Deanna Raybourn's Killers of a Certain Age, the phrase "necessary monsters" first appears in a flashback to 1986 when Constance Halliday, the mentor of the four female assassins, explains her philosophy to Billie Webster. Constance argues that the world needs people like them—killers who remove threats to peace and order, standing between "good and decent people and chaos." This makes them necessary, but also monstrous in the eyes of society. The term becomes a private justification for the women's lethal work and, over the course of the novel, evolves into a badge of honor and identity.

Where the Motif Reappears

The motif recurs at key moments in the story:

• 1986, Benscombe (Chapter Fourteen): Constance coins the phrase during her final conversation with Billie before her assisted suicide. She tells Billie, "We are necessary monsters," and Billie internalizes it as she helps Constance die peacefully.

• 1994, New York (Chapter Twenty-Two) : During the Fermín Bosque briefing, the women operate under this belief, though the phrase is not spoken aloud. The mission targets a Nazi-linked art smuggler, reinforcing the "necessary" aspect—eliminating evil that would otherwise flourish.

• Final Chapter, Venice (Chapter Thirty-Two) : After the successful elimination of Galina and the recovery of the Raphael painting Leda, the four women visit the Peggy Guggenheim Collection. They stand before Leonor Fini's Shepherdess of the Sphinxes and raise a toast "to Constance Halliday and themselves as 'necessary monsters.'" This moment transforms the phrase from a private creed into a public acknowledgment of their legacy.

How the Meaning Changes

Initially, "necessary monsters" is a pragmatic justification: assassins are tools that society needs but cannot openly accept. Constance presents it as a cold truth, a reason to abandon normal life and embrace the mission. Billie, who had been struggling with guilt and impulsiveness, uses it to suppress her humanity and focus on her work.

By the end of the novel, the meaning has shifted. The women, now in their sixties, have survived betrayal, hunted down their would-be killers, and retrieved a priceless artwork. The toast in Venice shows that they no longer see themselves as merely useful monsters. They actively choose this identity, celebrating their skill, loyalty, and impact. The phrase becomes a symbol of chosen family and subversive pride—they are monsters not because they are inhumane, but because they are unapologetically competent and dangerous, even in older age.

Character Connections

Billie Webster

Billie is the character most shaped by Constance's words. After hearing them, she "ruthlessly strangles" the part of herself that wanted softness and hope. The motif drives her narrative arc: from impulsive young assassin to a seasoned leader who ultimately reclaims her humanity without abandoning the identity.

Constance Halliday

The originator of the phrase, Constance embodies the necessary monster philosophy. She trained the women, chose Billie for her suicide because she trusted Billie's "humanity," and died on Midsummer night with Billie at her side. Her legacy lingers in every mission the women undertake.

Helen, Mary Alice, and Natalie

The other three women adopt the creed as well, though each interprets it through her own lens. Helen, the sober strategist; Mary Alice, the sharp-witted historian; and Natalie, the artist who brings emotional depth—they all accept the label in the final toast, affirming their collective identity.

Taverner

Billie's lover appears in the final scene on a motorcycle, offering a ride. His presence underscores that the women can have connections outside the group without losing their monstrous nature. Taverner loves Billie for who she is, necessary monster and all.

Theme Connections

Aging and Competence

The "necessary monsters" motif directly challenges ageism. The women are older, yet they are still lethal and effective. Their identity as necessary monsters is not diminished by gray hair or retirement plans; if anything, their decades of experience make them more dangerous. The phrase affirms that competence does not expire with youth.

Loyalty and Chosen Family

The four women form a tight-knit unit bound by shared secrets and survival. Calling themselves "necessary monsters" together reinforces their bond. They are each other's only true kin, and the label becomes a rallying cry that distinguishes them from ordinary people.

Deception and Disguise

Assassins are monsters only if discovered. The women's skill in disguise—playing Playboy Bunnies, elderly patients, or museum visitors—allows them to operate invisibly. The motif acknowledges that their monstrous work requires constant performance and hidden identities.

Revenge and Justice

The plot is driven by revenge—Galina Lazarov wants to kill them for her father's assassination. But the "necessary monsters" framing turns revenge into justice: the women killed Boris Lazarov because he was a Nazi collaborator and war criminal. They continue to eliminate threats, believing their violence serves a greater good.

Art and Legacy

The recovery of the Raphael Leda and the visit to the Peggy Guggenheim Collection link art to their identity. They see themselves as both destroyers and preservers—monsters who ensure beauty and history survive. The toast in front of Fini's painting solidifies their legacy as guardians of culture, even through violent means.

Study Questions and Answers

1. Why does Constance Halliday use the phrase "necessary monsters" rather than a more neutral term like "assassin" or "operative"?

Constance chooses "necessary monsters" to emphasize the moral ambiguity of their work. The word "monster" acknowledges that killing is inherently dehumanizing, yet "necessary" justifies it as essential for protecting society. This dual meaning forces Billie—and the reader—to grapple with the ethics of lethal violence committed for the greater good. The phrase is deliberately provocative, designed to create a shared identity that cannot be easily dismissed.

2. How does the meaning of "necessary monsters" change for the women between the 1986 flashback and the final chapter in Venice?

In 1986, the phrase is a justification given by an authority figure; Billie internalizes it to suppress her emotions and focus on the mission. By the final chapter, the women themselves speak it as a toast, reclaiming the label on their own terms. It evolves from an external mandate into an internal, chosen identity that celebrates their skill, loyalty, and legacy—no longer a burden but a badge of honor.

3. In what way does the recovered painting Leda connect to the "necessary monsters" motif?

The painting is a Raphael masterpiece looted by the Nazis, representing the cultural treasures the women fight to preserve. By retrieving it, they act as monsters who restore beauty and order. The painting's subject—Leda and the swan—also suggests transformation and hidden power, mirroring the women's own dual existence as both ordinary older women and lethal killers. The toast at the museum directly links their monster identity to art and legacy.

4. How does the motif challenge stereotypes about older women in fiction?

Older women are often portrayed as invisible, frail, or past their prime. The "necessary monsters" motif flips this stereotype by positioning the protagonists as still dangerous, competent, and essential. They are not retired grandmothers baking cookies but active agents of justice. The phrase declares that their value and capacity for violence do not diminish with age—if anything, experience makes them more formidable. The novel subverts the expectation that women over sixty should be passive and harmless.