★ Immersive dual-protagonist setup—a paper-based crime-solving experience more thrilling than a script-murder game. Going even further than immersive novels: you don't just play a character; you step into the shoes of two completely different figures—one after the other—the lieutenant of the Paris Police Department and an intern at a top criminal defense law firm. One focuses on crime-scene investigation, autopsy analysis, and interrogation breakthroughs; the other reviews case files, dissects witness testimonies, and crafts defense strategies. Two perspectives, three murder cases—experience the full "investigation–prosecution" loop. This isn't reading; it's solving crimes yourself.

★ Meets the modern adult's need for a smarter way to "kill time"—relaxing yet rewarding. Each case includes authentic forensic elements such as autopsy reports, interrogation transcripts, and evidence analysis, challenging you to observe, reason, and judge just like a real detective. Meanwhile, the legal-case segments test your logical rigor and attention to detail. Use this game to sharpen your reasoning, analytical skills, and judgment.

★ Crafted by an award-winning French author. Pétronelle Rostagny is a rising star in French detective fiction, winner of the Cognac Prize, the Black Iris Award, and many other honors, with nine bestselling novels and tens of thousands of devoted readers. She has distilled her deep understanding of criminal investigation and the law into three standalone cases. This means: meticulously constructed puzzles, an utterly immersive narrative atmosphere, and a level of satisfaction that far surpasses ordinary brainteasers.

Pétronelle Rostagny's Crime Investigation Manual: A book containing three brand-new, previously unpublished criminal case investigation guides.

Three all-new criminal cases, penned by the rising star of French detective fiction, Pétronelle Rostagny.

Sometimes as an experienced investigator, sometimes as a rookie legal intern—can you rise to the challenges that await you?

You will successively step into the shoes of Vincent Gorrant and Caroline Moreau, two characters with vastly different personalities and backgrounds, yet united by a common goal: to bring the truth to light in complex and gripping cases.

Through this book, you will find yourself immersed in three thrilling, self-contained investigations.

On one hand, you will play Lieutenant Vincent Gorrant, a judicial police officer at the Paris Criminal Police Directorate. Under the leadership of Commander Alexa Larochelle, you will be tasked with solving fiendishly difficult cases—where every detail matters and even the tiniest clue can alter the course of the investigation. You must rely on keen insight, rigorous logic, and precise judgment to unravel the mysteries and make sense of cunning, unpredictable crimes.

On the other hand, you will become Caroline Moreau, a bright and ambitious law student. As an intern at the prestigious law firm of the formidable criminal defense attorney Pauline Carrère, you will face a different kind of investigation. Here, there are no crime scenes—only thick files to pore over, testimonies to dissect, and strategies to devise, all in service of your legal arguments.

Conceived by the fresh voice of French detective fiction, Pétronelle Rostagny, this investigation manual will draw you into a dark and captivating world. Alongside Commander Alexa Larochelle and Attorney Pauline Carrère, you will alternate between two distinct roles, cracking three brand-new criminal cases.

• Room 101: Welcome to this case at the Paris Criminal Police Directorate
• Shadows of Suspicion: Dive into the intricate and fascinating world of criminal law
• The Art of Lying: Follow closely the reconstruction of a murder scene

Autopsy reports, interrogation transcripts, physical evidence… put your analytical and deductive skills to the ultimate test! These engrossing yet demanding cases will engage both your logic and your intuition.

All answers are provided at the end of the book.

Pétronille Rostagny
Born in Nice in 1980, Pétronille Rostagny studied at a business school in Angers, majoring in customer relationship marketing. In 2013, she moved to Dubai with her family for the second time, an experience that led her to take up writing. She created the novel “The Black Elf,” featuring Commander Alexa Laroch, who works at the Criminal Police Bureau located at 36 Rue de la Chaîne in Paris. Originally self-published, the book entered physical bookstores in June 2015 and was selected by the French reading club France Loisirs in 2016. The Alexa Laroch series has captivated 10,000 readers. In 2017 and 2018, the author published “Your Last Breath,” followed by the third installment, “We All Have Good Reasons to Kill,” which sold 30,000 copies. With eight novels to her name, Pétronille Rostagny has quickly become one of the most promising new voices in the French detective fiction scene.
Her success has been recognized with several prestigious awards: the Cognac Prize for Best French-Language Novel in 2022 and the Hôpital Lecture Prize in 2024 for “I Wanted to Kill You,” as well as the Brussels Black Iris Grand Prize in 2023 for “When You Open Your Eyes.” She is currently involved in adapting her last two novels for film and television.