Arthur Blackwood, a recently retired detective known for his sharp mind and relentless pursuit of justice, is pulled back into the shadows when a series of anonymous, cryptic letters arrive at his doorstep. Each one hints at a deadly conspiracy. Each one arrives with chilling precision. And each one builds toward a singular, horrifying promise: an assassination that will shatter everything.

With no badge, no backup, and time slipping through his fingers, Arthur must unravel a web of riddles, codes, and half-buried secrets.