Before we reached the altar, my three-year-old grandson squeezed my hand and whispered, “Grandpa, she was mean to Mommy.” Then he pointed toward my future wife and pulled a USB drive from his tiny pocket—one that would soon reveal the truth she had been hiding.

From somewhere across the hotel hallway, the mariachi band started playing the wrong song.

Someone laughed awkwardly.

Ernesto barely heard it.

He called Ramón, his oldest friend, former commander with the Investigative Police, and the man who was supposed to stand beside him as best man.