The Sinking City's Secret

Dr. Tamsin Rivers, a brilliant, driven scientist, is at the heart of a revolutionary communications project deep beneath the city. As the city's infrastructure inexplicably sinks at a uniform, impossible rate, Tamsin is thrust into crisis management. She must balance her ambition for scientific immortality with the growing suspicion that her own experiments may be responsible for the disaster. The city's fate, her career, and her sense of self are all at stake as she navigates corporate politics, public relations, and the mounting pressure to find answers. The city's slow collapse is both a literal and psychological threat, setting the stage for a story where reality itself begins to warp.

Tamsin's Unraveling Ambition

As the crisis deepens, Tamsin's obsession with her work grows. She is both lauded and feared within Myrica Dynamics, the tech giant funding her research. Her relationships with colleagues and her enigmatic handler, Lachlan Woodfield, are fraught with tension, power plays, and mutual distrust. Tamsin's need for control and recognition isolates her, even as she is forced to collaborate and delegate. The city's subsidence becomes a mirror for her own psychological descent—her certainty erodes, and cracks appear in her carefully constructed identity. The pressure to solve the mystery before disaster strikes pushes her to the edge.

The Impossible Door Appears

Amid the city's crisis, Tamsin discovers a new, personal anomaly: her own basement is distorting, stretching impossibly, and a door appears where none existed before. The door is perfectly ordinary in appearance but cannot be opened, and it resists all attempts at damage or analysis. Tamsin's scientific curiosity wars with mounting dread as she realizes the door's existence is physically impossible. The door becomes a symbol of her unraveling reality and the limits of her control. She is forced to hide this secret, fearing exposure and the loss of her life's work, even as the door's presence exerts a gravitational pull on her mind.

Doubles and Distortions

The door's mystery deepens when, after a period of mounting stress and sleepwalking, Tamsin encounters a perfect double of herself—Prime—emerging from the impossible door. Prime is physically identical but psychologically distinct: more empathetic, flexible, and eager to please. The appearance of the double coincides with accelerating distortions in the city and in Tamsin's own mind. The boundaries between self and other, original and copy, begin to blur. Tamsin's sense of reality is destabilized as she is forced to confront the possibility that she is not unique, and that her own actions may have summoned something she cannot control.

Prime Emerges, Questions Multiply

Tamsin, both fascinated and horrified, subjects Prime to a battery of tests, seeking to understand her origins and nature. Prime is compliant, intelligent, and quickly adapts to her new environment, even as Tamsin's paranoia grows. The two share knowledge, skills, and even domestic routines, but their differences become increasingly pronounced. Prime's existence challenges Tamsin's identity, agency, and moral compass. The city's crisis worsens, and the connection between the experiments, the door, and the doubles becomes more urgent. Tamsin's isolation deepens as she realizes she cannot trust anyone—not even herself.

Experiments in the Basement

The basement becomes a laboratory and a battleground. Tamsin and Prime conduct invasive experiments on each other, testing the limits of their humanity and their connection. The door remains impenetrable, but its influence grows. Tamsin's memory begins to slip, and her body suffers inexplicable injuries. The experiments reveal that Prime is not merely a copy but a mirror, reflecting and amplifying Tamsin's own flaws and desires. The scientific method fails in the face of the supernatural, and the basement transforms into a site of existential dread, where the boundaries of self, space, and time are all in flux.

Memory Slips and Paranoia

As Tamsin's memory degrades, she becomes increasingly paranoid and unstable. She forgets key events, people, and even her own actions. The distinction between waking and dreaming blurs, and she is haunted by visions of the door, the double, and her own past. Prime's influence grows as Tamsin weakens, and the power dynamic shifts. Tamsin's attempts to regain control—through violence, manipulation, or appeals to Lachlan—only accelerate her decline. The city's collapse mirrors her own, and the sense of impending doom becomes inescapable. The story becomes a psychological thriller, with Tamsin's mind as the primary battleground.

The Double's Ascendancy

Prime's competence, adaptability, and emotional intelligence allow her to navigate the crisis more effectively than Tamsin. She assumes Tamsin's public role, manages the city's response, and even wins the trust of Lachlan and Myrica Dynamics. Tamsin, increasingly sidelined and incapacitated, is forced to confront her own obsolescence. The double is no longer a threat to be contained but a replacement. The existential horror of being replaced—of losing not just one's work but one's very self—becomes acute. Tamsin's struggle shifts from external control to internal survival, as she seeks to reclaim her identity or find meaning in her dissolution.

Lachlan's Dangerous Oversight

Lachlan, Tamsin's handler and sometimes-confidante, becomes both a threat and a potential savior. Her attempts to manage Tamsin and contain the situation are complicated by her own divided loyalties and the emergence of her own double. The power dynamics between Tamsin, Prime, and Lachlan become a deadly game of trust, manipulation, and violence. Lachlan's presence is both stabilizing and destabilizing, forcing Tamsin to confront the consequences of her actions and the limits of her autonomy. The story's tension peaks as all three women are drawn into a confrontation that will determine who survives and who is erased.

Violence, Surgery, and Control

The struggle for control becomes physical and brutal. Tamsin, desperate to reclaim her agency, resorts to violence—against Prime, against herself, and against Lachlan's double. Surgery, restraint, and bodily mutilation become tools in the fight for survival and identity. The violence is both literal and symbolic, representing the tearing apart of the self and the impossibility of returning to a previous wholeness. The story's horror is at its most visceral, as the characters are reduced to bodies in pain, fighting for dominance in a world that no longer obeys the rules of science or sanity.

The City Collapses

As the city's infrastructure fails catastrophically, the personal and the cosmic collapse converge. Buildings fall, chaos reigns, and the consequences of Tamsin's ambition become undeniable. The node labs, the door, and the doubles are all implicated in the disaster. Tamsin and Prime's fates are now inseparable from the city's. The collapse is both an ending and a beginning—a necessary destruction that makes way for transformation. The story's scale expands from the personal to the apocalyptic, and the stakes become existential: survival, meaning, and the possibility of redemption.

The Final Descent

With the city in ruins and her own mind and body broken, Tamsin descends one last time into the basement. The door, now the only remaining mystery, calls to her with irresistible force. Prime is there, waiting, both adversary and twin. The final confrontation is not a battle but a reckoning—a negotiation of identity, agency, and the meaning of selfhood. The door is both a literal and metaphorical threshold, offering the possibility of escape, annihilation, or transformation. Tamsin must choose whether to step through, to surrender, or to fight for what remains of herself.

Through the Door, Alone

In the story's climax, Tamsin and Prime enact the ritual of the door. The boundaries between them blur, and the distinction between original and double becomes meaningless. The door opens onto an abyss, and Tamsin must let go—of control, of fear, of her old self. The act of passing through the door is both a death and a rebirth, a sacrifice and a liberation. The story's central question—what does it take to open the door?—is answered not with certainty but with surrender. Tamsin emerges changed, alone, and free from the cycle of doubling and replacement.

Aftermath and Reckoning

In the aftermath, Tamsin is left to rebuild her life in a world forever altered by her actions. The city is scarred but stable, the doors are gone, and Prime is no more. Tamsin's memories, identity, and relationships are all changed, but she is alive and, for the first time, at peace with uncertainty. The story ends not with triumph or tragedy, but with acceptance—a recognition that the self is always in flux, that control is an illusion, and that meaning is found not in mastery but in the willingness to change. The final reckoning is not with the double, but with oneself.

Characters

Dr. Tamsin Rivers

Tamsin is a brilliant, driven physicist whose ambition to revolutionize communications technology is matched only by her need for control and recognition. Her relationships are transactional, her empathy limited, and her self-image fragile. As the city's crisis unfolds, Tamsin's psychological stability unravels—her memory slips, her paranoia grows, and her sense of self fractures. The appearance of her double, Prime, forces her to confront her own flaws, desires, and the limits of scientific rationality. Tamsin's journey is one of dissolution and transformation: from master of her domain to a haunted, humbled survivor, ultimately forced to accept uncertainty and change.

Prime (Tamsin's Double)

Prime is Tamsin's physical double, emerging from the impossible door as both a reflection and a distortion. She is more flexible, emotionally intelligent, and eager to please, but also capable of manipulation and violence. Prime's existence destabilizes Tamsin's identity, challenging her assumptions about uniqueness, agency, and morality. As Prime adapts, she becomes increasingly competent, eventually surpassing Tamsin in public and professional roles. Prime's motivations are ambiguous—she seeks connection, understanding, and perhaps her own form of survival. Her presence is both a threat and an opportunity, forcing Tamsin to reckon with the parts of herself she cannot control or accept.

Lachlan Woodfield

Lachlan is Tamsin's corporate handler, responsible for both enabling and containing her. She is physically imposing, emotionally reserved, and ruthlessly pragmatic. Lachlan's relationship with Tamsin is a complex dance of power, trust, and mutual suspicion, tinged with unspoken attraction and resentment. As the crisis escalates, Lachlan's own boundaries are tested—she becomes both a potential savior and a threat, especially as she confronts her own double. Lachlan's role is to manage risk, but she is ultimately forced to choose between loyalty to the corporation and loyalty to Tamsin as a person. Her fate is intertwined with Tamsin's, and her presence is both stabilizing and destabilizing.

Cara Vigneault

Cara is Tamsin's assistant, efficient and discreet, often caught between conflicting loyalties. She is a minor but crucial character, representing the ordinary people affected by the extraordinary events. Cara's role is to facilitate Tamsin's work, but she also serves as a witness to Tamsin's decline and the ethical ambiguities of the project. Her quiet competence and understated concern provide a counterpoint to the high-stakes drama, grounding the story in the reality of human relationships and the costs of ambition.

The City of San Siroco

The city is more than a setting—it is a character in its own right, reflecting and amplifying the psychological and existential crises of the protagonists. Its slow, impossible subsidence is both a literal disaster and a metaphor for the erosion of certainty, identity, and control. The city's fate is inseparable from Tamsin's, and its collapse is both a consequence and a catalyst for the story's central conflicts. The city's suffering is a reminder of the broader costs of unchecked ambition and the limits of human understanding.

The Door

The impossible door in Tamsin's basement is both a plot device and a character—a presence that exerts a gravitational pull on everyone who encounters it. It is a symbol of the limits of science, the permeability of reality, and the inevitability of change. The door's refusal to open, its resistance to analysis, and its eventual function as a portal all serve to destabilize the narrative and the characters' sense of self. The door is both a challenge and an invitation, a test of courage and a demand for surrender.

The Doubles (Lachlan's Double, Penrose's Double)

The appearance of other doubles—Lachlan's, Penrose the cat's—serves to expand the story's central theme: the instability of identity and the dangers of unchecked replication. These doubles are both comic and horrific, reminders that the boundaries between self and other, original and copy, are always porous. Their presence escalates the crisis, forcing the characters to confront the possibility that no one is unique, and that survival may require sacrifice or annihilation.

Mr. Thomas

Mr. Thomas is the owner of Myrica Dynamics, the ultimate authority behind Tamsin's work. He is largely absent from the narrative, but his influence is felt in every decision, every risk calculation, and every act of containment. Mr. Thomas represents the impersonal, amoral logic of corporate power—the drive for innovation at any cost, the willingness to sacrifice individuals for the greater good (or profit). His presence is a reminder that the story's conflicts are not just personal, but systemic.

Yvette Olsen

Yvette is one of Tamsin's key collaborators, a scientist who provides both support and skepticism. She is less ambitious than Tamsin, more attuned to the ethical and practical implications of their work. Yvette's role is to challenge Tamsin's assumptions, to ask the questions Tamsin refuses to consider, and to serve as a potential ally or adversary depending on the shifting dynamics of trust and power.

Isaac Torrence

Torrence is a young, talented researcher eager to rise in the ranks. His ambition and willingness to bend the truth make him both a useful tool and a potential threat. Torrence's fate is a warning to Tamsin: the system that rewards brilliance and ruthlessness is also quick to discard those who become liabilities. His trajectory mirrors Tamsin's own, and his downfall is both a source of satisfaction and a harbinger of what awaits those who push too far.

Plot Devices

The Impossible Door

The door is the story's central plot device, functioning as both a literal and metaphorical threshold. Its appearance signals the breakdown of reality and the permeability of identity. The door's refusal to open, its resistance to analysis, and its eventual function as a portal all serve to destabilize the narrative and the characters' sense of self. The door is both a challenge and an invitation, a test of courage and a demand for surrender. Its presence drives the plot, forcing the characters to confront the unknown and to choose between control and transformation.

Doubling and Mirroring

The appearance of doubles—Tamsin's, Lachlan's, Penrose's—serves as both a plot engine and a thematic exploration of identity, agency, and the fear of replacement. The doubles are not mere copies but mirrors, reflecting and amplifying the flaws, desires, and anxieties of the originals. The process of doubling is both a horror and an opportunity, forcing the characters to confront the parts of themselves they cannot control or accept. The narrative structure itself mirrors this doubling, with parallel arcs, shifting perspectives, and recursive motifs.

Memory Loss and Unreliable Narration

Tamsin's memory slips, her perception distorts, and the boundaries between waking and dreaming blur. The story employs unreliable narration, recursive flashbacks, and dream sequences to destabilize the reader's sense of reality. The loss of memory is both a symptom and a cause of Tamsin's dissolution, mirroring the city's collapse and the breakdown of scientific rationality. The narrative structure is fragmented, reflecting the characters' psychological fragmentation.

Scientific Rationality versus the Supernatural

The story is structured as a scientific mystery, with Tamsin and her colleagues employing the tools of rational inquiry to solve the city's crisis and the mystery of the door. But the supernatural elements—the door, the doubles, the impossible distortions—resist explanation, undermining the very foundations of science. The tension between rationality and the unknown drives the plot, forcing the characters to confront the limits of their knowledge and the necessity of surrender.

Power Dynamics and Corporate Control

The story is set within the high-stakes world of corporate science, where ambition is rewarded and failure is punished. The power dynamics between Tamsin, Prime, Lachlan, and Myrica Dynamics are central to the plot. The corporation's need for control, containment, and plausible deniability shapes every decision, every risk calculation, and every act of violence or mercy. The story's structure mirrors the logic of the corporation: hierarchical, compartmentalized, and ultimately indifferent to individual suffering.

Foreshadowing and Recursion

The story is rich in foreshadowing, with early events and motifs recurring in altered forms. The appearance of the door, the doubling of characters, the collapse of the city—all are anticipated and mirrored throughout the narrative. The ending echoes the beginning, with Tamsin once again facing a door, forced to choose between control and surrender, self and other, the known and the unknown.

Analysis

Caitlin Starling's Last to Leave the Room is a masterful blend of psychological horror, speculative science, and existential thriller. At its core, the novel interrogates the nature of identity, the limits of scientific rationality, and the terror of being replaced—by technology, by ambition, by one's own shadow. The impossible door and the phenomenon of doubling serve as both plot engines and metaphors for the instability of self in a world governed by systems beyond individual control. The city's collapse mirrors Tamsin's psychological dissolution, and the story's recursive structure forces both protagonist and reader to confront the impossibility of returning to a previous wholeness. The novel's ultimate lesson is one of acceptance: that meaning is found not in mastery or control, but in the willingness to change, to let go, and to face the unknown. In a world where ambition and innovation threaten to unmoor us from ourselves, Last to Leave the Room is a chilling, timely meditation on the costs—and the necessity—of transformation.

Last updated: September 25, 2025