Tess Stimson's One in Three is a gripping psychological thriller that delves into the complexities of love, betrayal, and the lengths to which individuals will go to protect their own interests. The novel opens with a tantalizing premise: two women, both intertwined with the same man, find themselves at the center of a murder investigation. This setup not only hooks the reader but also sets the stage for a deep exploration of character motivations and the darker sides of human nature.

The story revolves around Louise, a woman grappling with the emotional fallout of her husband Andrew leaving her for Caz, the 'other woman' who has now become his wife. Stimson expertly captures Louise's turmoil as she oscillates between resentment and longing. Her character is richly developed; we see her transformation from a heartbroken ex-wife to a woman on a mission to reclaim her past. Louise's obsession with Caz and her determination to undermine her rival add layers to her character, making her both relatable and, at times, unsettling.

Caz, on the other hand, is painted as the seemingly perfect wife, yet as the narrative unfolds, Stimson reveals the cracks in her facade. The tension between Louise and Caz is palpable, and their interactions are charged with a mix of civility and underlying hostility. Stimson's portrayal of their rivalry is nuanced, showcasing how both women are victims of their circumstances, yet also complicit in their own suffering. This duality makes the reader question who the real antagonist is, a theme that resonates throughout the novel.

As Louise begins to dig into Caz's past, the plot thickens, revealing secrets that both women have kept hidden. Stimson's skillful pacing keeps the reader engaged, with each revelation adding depth to the narrative. The exploration of their shared history with Andrew serves as a powerful commentary on how love can become a weapon, and how the desire for revenge can cloud judgment. The author deftly navigates the emotional landscape of jealousy and betrayal, making the reader empathize with both women, even as they spiral into a dangerous game of one-upmanship.

The murder of Andrew during a family celebration serves as the catalyst for the climax of the story. Stimson's choice to have both women found standing over the body is a brilliant narrative twist that heightens the suspense. The question of who killed Andrew looms large, and as the investigation unfolds, the reader is taken on a rollercoaster ride of twists and turns. Stimson masterfully plays with the reader's expectations, leading them down various paths before revealing the truth. This element of surprise is reminiscent of works by authors like Gillian Flynn and Paula Hawkins, who also excel in crafting intricate plots with unreliable narrators.

One of the most compelling themes in One in Three is the exploration of identity and self-worth. Both Louise and Caz are forced to confront who they are outside of their relationships with Andrew. Louise's journey is particularly poignant as she grapples with her sense of self after being discarded. Stimson poignantly illustrates how the end of a marriage can lead to a profound identity crisis, a theme that resonates with many readers who have experienced similar heartbreak. Caz, too, must confront her own insecurities and the reality of her marriage, leading to a powerful moment of self-realization that adds depth to her character arc.

The novel also raises questions about societal perceptions of women, particularly in the context of relationships. The phrase "It's always the wife" serves as a haunting reminder of the stereotypes that women face, especially in situations involving infidelity and murder. Stimson challenges these stereotypes by presenting two complex female characters who defy easy categorization. This exploration of gender dynamics adds an additional layer of richness to the narrative, making it not just a thriller but also a commentary on the societal expectations placed on women.

Stimson's writing style is engaging and accessible, with a keen eye for detail that brings the characters and settings to life. The dialogue is sharp and realistic, capturing the nuances of human interaction and the underlying tensions that exist between the characters. The pacing is well-balanced, with moments of introspection interspersed with high-stakes drama, ensuring that the reader remains invested in the outcome.

In conclusion, One in Three is a thought-provoking and suspenseful read that will keep readers on the edge of their seats. Tess Stimson has crafted a narrative that not only entertains but also invites reflection on the complexities of love, identity, and the darker aspects of human nature. The interplay between Louise and Caz, coupled with the shocking twists and turns of the plot, makes this novel a standout in the psychological thriller genre. For those who enjoy stories that delve into the intricacies of relationships and the human psyche, One in Three is a must-read.