Columbians

The group referred to only as "the Columbians" is a drug cartel. In Zero Sum Game Pithica has taken them over, or "defanged" them, and set up Courtney Polk as a truck driver (drug smuggler). When she runs a red light and is caught, the Columbians kill the cops and take Courtney back. At this point Dawna hires Cas ostensibly to retrieve Courtney. Uncoincidentally, Rio is undercover with the Columbians in his quest to take down Pithica, and happens to be working right at the base where they take Courtney.

Part of what makes taking down Pithica a zero sum game is that it routes money back to organizations such as the Columbians, to do with as they please. After Zero Sum Game, Pithica is no longer holding them back.