A corpse in a burning guesthouse. A dead man whose secrets were never meant to be uncovered.

Pasadena, early 2000s. David Endicott has returned from military police duty in Iraq, with his father’s murder still unsolved, ready to find a job and start fresh with his girlfriend, Nor Campbell, a professional chef. Nor works for billionaire Baulden Grey.

His first case as an unlicensed private investigator seems simple enough. Seven days. Three questions. Who was the corpse in Grey’s guesthouse? How did he get past Southern California’s best security? What did he come for?

It would never remain simple.

The dead man left behind more than a corpse. A dusting of powdered wings from a rare Chinese butterfly, the Golden Yellow, begins a trail through a stolen photograph archive, a gang’s torture chamber in Garden Grove, and a long-abandoned state hospital basement where something delicate is still cultivated into something deadly. The trail cuts through the politics of California’s gubernatorial election.

Every thread boomerangs back to the Human Betterment Foundation, the Pasadena organization that helped inspire the Nazi Party’s racial-cleansing campaign. The Foundation is long gone. Its blueprint is not.

Endicott has days to stop a mass event before it crushes him, Nor, and thousands of people no one will miss.

Seventy years ago, they called it science. This time, they’re calling it a cure.