Plan Interrupted by Valerie J. Clarizio brings to the table a robust mix of romance, self-discovery, and mystery that keeps readers engrossed from the first page to the last. The narrative delves into the life of its protagonist, Carley, exploring themes of personal growth, second chances, and the complexities of human emotions with a commendable depth of insight and sensitivity.

The plot centers around Carley, a driven woman whose life is as meticulously planned as it is successful. Her high-powered career and financial success, however, mask an undercurrent of dissatisfaction and unfulfilled personal dreams. The arrival of Joe Cardinale, her lost love, acts as the catalyst that disrupts her perfectly structured life. Joe's return not only stirs unresolved feelings but also compels Carley to reassess her life’s direction, testing her ability to handle unexpected changes and challenging her to redefine her understanding of true happiness.

Clarizio’s strengths lie not just in constructing relatable characters but also in her ability to craft a multi-layered narrative that engages and challenges the reader. Carley’s character evolution is portrayed with a great deal of nuance and authenticity. As the story progresses, she transforms from a control-centric individual to someone who learns to embrace the unpredictabilities of life. This transition, fraught with emotional and psychological upheavals, is depicted with a truthfulness that many will find resonant.

The reintroduction of Joe into Carley's life is handled with a palpable sense of tenderness and complexity. Clarizio ensures that their past and present intermingle seamlessly, using flashbacks effectively to layer their relationship and heighten the emotional stakes. Joe’s character, with his protective yet understanding nature, is a perfect foil to Carley’s initially rigid demeanor. The dynamic between them oscillates between tender reconciliations and poignant confrontations, making their journey a compelling core for the narrative.

On another front, the book does an admirable job in weaving a subplot involving a mysterious stalker. This element introduces a suspenseful twist to the romance and personal growth narrative, providing a good pace and keeping readers intrigued. The suspense is well-maintained, with clues dispensed at a steady rate that compels the audience to keep turning the pages. The resolution of this mystery is both satisfying and somewhat surprising, adding a good closure to the overarching tension that builds throughout the book.

An aspect where Clarizio particularly excels is in the setting descriptions that convincingly create the backdrop against which the characters’ stories unfold. The settings, from bustling cityscapes to serene suburban locales, are vividly described, enhancing the mood and helping in the overall world-building. Such details not only give a sense of place but also complement the inner journeys of the characters.

However, while the blend of romance and mystery is generally well-handled, there are moments where the transition between these two tones could be smoother. At times, the shift from intimate, introspective moments to high-stakes drama can feel somewhat abrupt. Nonetheless, this does little to mar the engaging rhythm of the story and is mostly a minor quibble in an otherwise sharply edited book.

The dialogue within Plan Interrupted deserves a special mention for its authenticity and fluidity. Conversations between characters are crafted with a keen ear for realism, capturing a wide range of emotions — from witty banter to soul-searching discussions. These interactions play a crucial role in fleshing out the characters and advancing the plot, making them fundamental to the reader’s engagement.

In conclusion, Plan Interrupted by Valerie J. Clarizio is a thoughtfully written novel that covers a gamut of human experiences and emotions. It is an exploration of love, loss, and the courage to pursue true happiness against the odds. For those who enjoy a narrative that provides both a heartwarming romance and a gripping mystery, this book is a commendable choice. Clarizio’s skillful storytelling and multi-dimensional characters ensure that readers will find both entertainment and emotional resonance in the pages of this engaging novel.