Strange and unpredictable murders have occurred one after another in the international metropolis "Jiangcheng City", leaving a special artificial aroma at the scene. Wen Jing, a criminal profiler who returned from studying in the UK, was forced to form a partnership with Lu Chen, the leader of the serious crime team who advocates absolute rationality, with her extraordinary sense of smell and ability.
From the initial conflict of ideas to mutual sympathy, Wen Jing and Lu Chen formed a special investigation team with forensic doctor Su Mian and strange police officer Zhao Li. They used their respective specialties to work together to solve a series of "perfect crimes" filled with strange aromas. In the process of solving the case, Wen Jing discovered that all the clues pointed to a mysterious organization called "Collectors", and the organization's modus operandi was exactly the same as the unsolved case she failed to solve in the UK many years ago, which led to the death of her mentor.
Four people and a cat walk side by side in the darkness. What they have to face is not only highly intelligent criminals and intricate puzzles, but also the abyss of human nature and the nightmares of the past. This is a journey of using intuition to challenge logic and emotion to fight cold justice.
