He can deconstruct any poison. But he cannot escape his own.

Dr. Luc Dubois is a ghost, a man haunted by the ruins of his former life. Once a rising star in the Paris Sûreté, his revolutionary forensic methods led to a scandal that left him disgraced, destitute, and dependent on the quiet oblivion of the opium pipe. Now, he operates in the shadows, his brilliant mind a forgotten relic in the dawn of a new scientific age. But when a phantom killer begins to stalk the gilded cage of Belle Époque society, leaving a trail of powerful dead men and the lingering scent of a spectral perfume, Luc is pulled back into the world that cast him out.

Secretly hired by a powerful industrialist, Luc must do what the baffled Sûreté cannot: hunt a killer who leaves no clues. Armed with his custom-built chemical kit and a mind that sees the world as a series of complex equations, he descends into the city's opulent and corrupt heart. From the debaucherous meetings of a secret society to the private salons of the city's most desirable courtesans, Luc uncovers a web of blackmail, treason, and murder that threatens to bring the Republic to its knees.

The closer he gets to the Perfumer, the more personal the hunt becomes. The killer is a fellow artist of chemistry, a dark mirror of Luc's own genius, and their duel plays out in the language of molecules and motives. To stop the murders, Luc must not only stay one step ahead of a murderer but also of the Sûreté inspector who blames him for his own past failures.

As the body count rises and the conspiracy deepens, Luc is forced to confront the terrible truth that his addiction, the source of his shame, may also be the key to the entire investigation. In a breathtaking race against time, he must harness his own demons to unmask a monster, knowing that one false step will not only lead to his death, but will allow a perfect, elegant, and diabolical evil to walk free.

Perfect for fans of Caleb Carr's The Alienist, the intricate plotting of Anthony Horowitz, and the dark, atmospheric suspense of Tana French.