Garrison leaned in. “Okay, you remember how just before Sheriff Ross died, the border was in turmoil, right? Two cartels, Nemesio and the Serrano Brothers—Los Hermanos Serrano—fighting over control of the smuggling routes through Chihuahua and the Ojinaga corridor. This happens all the time. We saw it in Juárez, Nuevo Laredo, you name it. There’s a truce for a while, an agreement, and then someone breaks it or tries to strong-arm the other and all hell breaks loose. Ross probably got caught in the crossfire of something like that. We always suspected Ross was working for Nemesio, mainly because of the Rudy Reynosa connection, but who knows? Ross may have been working with both cartels, or cheating them both. Personally, I think he got greedy, and it got him killed.”

“Whatever Ross was into also got Rodolfo Reynosa killed.”

“True. And Rudy was definitely working for Nemesio.”

“And you.”

Garrison nodded. “Fair enough. Look, we’ll never know exactly what happened back then, but the dynamic today is the same. It’s always the same. Bad guys over there fighting for control of their assets here.” He pointed at the scrub around them. “This is where they make all the money, Chris.”

“Fine, makes sense. But this is all ancient history.”

“Not that ancient.”

Chris shook his head, conceding the point. “And what does any of this have to do with killing students, kids?”

“That little war between the Serrano Brothers and Nemesio never really ended. It’s been going on, all along, below the surface. Guerrilla warfare. New battlegrounds, new tactics. The prevailing wisdom is that one of those cartels purposely ordered that attack to draw a forceful response from the Mexican government. It was a setup, something so horrible even the politicians couldn’t ignore it. No one could. No different from the bodies they leave stacked in the streets or the big banners they hang from the bridges over there, what they call a narcomanta. The bus attack was a threat, another bloody message the cartels love to send each other and the Mexican government. Right now, the full strength of the Mexican federal law enforcement and military is sweeping through Chihuahua, looking for scalps. Message received, mission accomplished.”

“So this was all done just to blame the other?”

“Three dead, six injured, nineteen vanished. All teenagers. It’s all over the news. The whole world is watching. Someone will go down, and we believe Nemesio is set for the fall. They’ve held on to Ojinaga longer than anyone else, but now, finally, their grip is slipping. I’ve seen some reports that indicate the Serrano Brothers are all over this area now. The bus attack may be the final push.”

“And by ‘this area,’ you mean right here, the Big Bend.”