Season three continues the Gecko brothers' saga, as they fight their way through the world of culebras, the vampire-snake hybrids that control hidden empires in Texas and Mexico. Once the baddest outlaws in the land, Seth and Richie made a run for the border two years ago, to save their lives – and their fortune. They ran headlong into a bar full of bloodsuckers and bandits, facing off with the vampire goddess, Santánico. The Geckos joined her cause, and they settled an old score. It won them a place in the culebra world. Now, that world is about to explode, and new enemies are gathering – dark forces, hell-bent on destruction and domination. It's up to the Geckos to stop them – but they can't do it alone.

Season Two begins with our characters in their separate worlds - Santanico and Richie are outside Houston, living like Bonnie and Clyde; Seth and Kate are scraping by South of the Border; and Freddie Gonzalez is protecting his wife and young daughter in a Houston suburb. And Carlos Madrigal and Scott Fuller emerge from the Titty Twister, changed men. They will all come together once again - this time facing off against an even bigger threat.

Seth Gecko, a hardened bank robber who has just been broken out of prison by his mentally unstable brother Richie, who has recently begun having visions of a mysterious woman who urges him to kill and invites him to find her. Meanwhile, after the death of the family matriarch, former pastor Jacob Fuller is taking an RV vacation into Mexico with his daughter Katie and adopted son Scott. The lives of the Geckos and the Fullers become entwined as the brothers attempt to outrun the authorities and cross the Texas border into Mexico, where they will be sheltered by Cartel boss Don Carlos. They are pursued by Texas Ranger Freddie Gonzalez, who is out to avenge the death of his partner and mentor Earl McGraw, whom the Geckos killed in a botched hostage situation.