In Her Mind, authored by Blake Pierce, offers readers a psychological thriller that ambitiously delves into the complexities of human psychology, intertwined with a gripping narrative of crime solving. This novel is one of the recent additions to Pierce's expansive portfolio of thrill-suspense literature, which promises and largely succeeds in hooking readers from the outset with its intricate plot and well-rounded characters.

The protagonist, Rebecca, is a seasoned FBI agent tasked with solving a series of convoluted murders that seem interconnected. What makes her stand out in the crime thriller genre is not just her grit and tenacity, which are almost prerequisites for the archetype, but her profound psychological insights that Pierce has masterfully developed. These mental acuities are not just innate but are also a product of her turbulent past—a narrative element that Pierce uses adeptly to add depth to her character.

As the book unfolds, the reader is drawn into a complex web of deception, with each chapter peeling back layers of the mystery. Pierce employs a dual narrative technique that oscillates between Rebecca’s current investigations and her past experiences, providing a backstory that is directly tied to her present actions and thoughts. This interplay between past and present is one of the novel's strengths, allowing for a rich, character-driven story.

The psychological aspect of In Her Mind is particularly compelling. Pierce's depiction of the murderer’s psyche is nuanced and disturbing, offering an intriguing contrast to Rebecca's methodology in tracking him down. This psychological battleground forms the core of the narrative, bringing a visceral intensity to the interactions and a deeper philosophical question about nature versus nurture in shaping a person's destiny.

However, the book is not without its flaws. At times, the pace stumbles, particularly in the middle chapters where the dual narrative seems to overextend itself. While the back-and-forth between past and present is generally well-executed, there are moments where it feels more like a narrative convenience rather than a seamless part of the storytelling. Additionally, while most characters are well fleshed out, some of the secondary characters come off as underdeveloped, serving more as plot devices than as integral parts of the story.

The setting of the novel also deserves a mention. Pierce uses the backdrop of a gloomy, tension-soaked city that mirrors the turmoil within the characters. The detailed descriptions of the urban environment not only helps in grounding the story’s gritty themes but also enhances the overall moodiness of the narrative. It acts almost as another character, pushing the main characters into emotional corners, from which they often emerge with startling realizations or bruised egos.

From a literary perspective, Pierce’s writing is sharp and engaging. His prose is fluid, with dialogues that are crisp and laden with meaning, often carrying the weight of psychological insights. The thematic exploration of memory, trauma, and redemption is woven seamlessly into the plot, challenging the reader to consider the moral ambiguities of each character's actions.

Despite its pacing issues and occasional predictability in plot twists, In Her Mind holds up as a solid psychological thriller. What could easily have been another by-the-numbers detective story is elevated by its deep psychological underpinnings and the strong, though flawed, female protagonist. For fans of the genre looking for a story that successfully blends action with introspection, this book will satisfy. Moreover, those interested in the psychological aspects of crime and the inherent questions of right and wrong it poses, will find this book particularly thought-provoking.

In conclusion, In Her Mind by Blake Pierce is a commendable work that represents the complexity and excitement of the psychological thriller genre well. Though it could improve in pacing and character development, the novel’s core strengths in mood, setting, and principal character development are robust. It is a book that both entertains and provokes, making it a recommended read for those enthralled by the darker aspects of human psychology intertwined with suspenseful storytelling.