Los Angeles 1930s. It was the last roundup for the gentleman in the three-piece suit, bobbing up and down in the moonlight like a rodeo cowboy on the back of a pumpjack. The metal horsehead pump was one of the smaller ones in the Inglewood Oil Field. Perhaps eight feet high at best. The victim's legs, torso, and right hand were strapped to the walking beam, leaving his left arm to flop around with the rocking horse motion.

It was a bizarre sight in an equally bizarre landscape, filled as far as the eye could see with a forest of hundred-foot-high wood oil derricks, their relentless motion oblivious to the human tragedy on display.

The case would plunge Detective Mathieu into the ruthless world of oil barons in 1930s Los Angeles.