The Hollows are the wrong side of the tracks – a neighborhood for poor Votans and humans who live on the fringes of society. The alleys are dotted with shady businesses and shadier characters. A Sensoth nicknamed "Fozzi" runs a well-respected roller garage there. The Hollows are controlled by Datak Tarr, a Castithan gangster with ties to the Votanis Collective. 
In the Pilot episode, Kenya Rosewater sends Joshua Nolan to The Hollows as the best place to earn “fast money.” While in The Hollows, Nolan fights a bioman and wins, earning himself a nice pile of scrip, but Datak Tarr manages to take his winnings back, showing just how much control he has over the area.
Castithan shaming rituals also take place in The Hollows as seen in Down in the Ground Where the Dead Men Go. Mayor Amanda Rosewater, who disapproves of shaming rituals, wants to see them confined to The Hollows and out of the rest of the town. Although she does not approve of the rituals, she will not stop Castithans from practicing their cultural customs.
In A Well Respected Man, Nolan arrests two Castithans who appear to be making a drug trade in the Hollows. He confiscates all the money and illegal weapons from their car as retaliation after their boss, Datak Tarr, left a dead body on Nolan’s doorstep. Nolan is on a warpath to take down Datak for every one of his illegal actions. Unfortunately, Amanda later learns that Datak had been making underhand deals with members of her own town council to smuggle these weapons in to Defiance. He seems almost untouchable due to his sizeable criminal network, largely based in the Hollows.