London, 1893.A body is found in the fog.Her throat is slit.Her skin is embroidered with crimson thread.And stitched into her flesh: a number.By morning, the Thames shines an unnatural green.By night, London understands the truth-this killer doesn't strike at random. He counts.The newspapers name him The Crimson Thread Falcon.Each color that stains the river marks another victim.Inspector Elias Crowe believes in facts, not fear. Chemistry, not superstition. But when the murders follow a precise sequence and the symbols grow more elaborate, even Crowe must admit the terrifying possibility: this is not madness-it is design.With the help of Eleanor, a botanist who reads poisons like fingerprints, and Bee Holloway, a fragile orphan carrying a secret that could make her the next number, Crowe races to unravel a pattern buried beneath layers of Victorian respectability.Because beneath London's fog lies something far darker than crime: a history of burned factories, false charity, and powerful men whose sins were never punished.Now, someone is rewriting that history-with a needle in one hand and a blade in the other.Perfect for fans of C.J. Sansom, Laura Purcell, and readers who love dark historical thrillers with serial-killer tension.A gripping gothic mystery where science battles obsession, and every answer comes too late.The numbers are rising.The thread is tightening.And the next stitch may already be yours.