In the ever-changing world of Mexican cartels, it often is hard to "know the players without a scorecard." Such is the case as cartels battle for control of the Mexican state of Tamaulipas and the lucrative border town of Nuevo Laredo.

In this Episode, I trace the lineage of the infamous Los Zetas cartel to one of the prime combatants in Nuevo Laredo, the Cartel del Noreste or CDN. I also discuss other Zeta-related splinter groups, including the Zetas Vieja Escuela, or Old School Zetas.

Finally, I look at the now fractionalized Gulf Cartel, and discuss its several groups, including the Scorpions, Cyclones, Metros, and Rojos, including their interactions and common grounds.