“You knew him in Vietnam?”

“I knew him,” I said. I glanced past her shoulder at the video screen. “You’ve got four kings. Welcome to Louisiana.”

ON THE WAY BACK to the office, I asked myself why I hadn’t told her I had been friends with her father in Miami. But maybe the memory was just too unpleasant to revisit, I thought. Maybe she had never learned that her father had been enticed into aiding and abetting the robbery of the armored car, if indeed that’s what happened. Why let the past injure the innocent? I told myself.

No, that was not it. She had paused before she acknowledged her father. As any investigative law officer will tell you, when witnesses or suspects or even ordinary citizens hesitate before answering a question, it’s because they are deciding whether they should either conceal information or outright lie about it.

It was almost 5 p.m. when I got back to the department. Wally, our dispatcher, told me there had been a homicide by gunshot wound on the bayou, amid a cluster of houses upstream from the sugar mill. I gave the serial numbers on the bills to a detective in our robbery unit and asked him to run them through our Internet connection to the U.S. Treasury Department. Then I tried to forget the image of Dallas Klein kneeling on a sidewalk, his fingers laced behind his head.

The sheriff of Iberia Parish was Helen Soileau. She had begun her career in law enforcement as a meter maid with NOPD, then had patrolled the Desire district and Gird Town and worked Narcotics in the French Quarter. She wore jeans or slacks, carried herself like a male athlete, and possessed a strange kind of androgynous beauty. Her face could be sensuous and warm, almost seductive, but it could change while you were talking to her, as though not only two genders but two different people lived inside her. People who saw her in one photograph often did not recognize her in another.