When retired Lt. Alex Villanueva announces his candidacy for sheriff in 2017, no one takes him seriously. But with the support of the local Democratic party, immigrant rights activists, and lots of political savvy, he pulls off a shocking defeat of the sitting sheriff – something that hasn’t happened in over 100 years. Almost as soon as he takes office, Villanueva re-hires a former deputy (and friend) who was fired for domestic violence and lying, and things begin to go off the rails.