Supernatural: Bloodlines producer Andrew Dabb previews the potential spinoff and the backdoor pilot he penned.

This week’s Supernatural episode “Bloodlines” sees the Winchester brothers hitting Chicago and discovering that five monster families are ruling the city’s underbelly. They meet Ennis (Lucien Laviscount), an aspiring hunter whose fiance was killed in the monster war crossfire.

“For us, as we were cracking this pilot, what we wanted to avoid doing was, like, Supernatural: Miami, where we take another group of hunters and put them in another place and just focus on them,” Dabb tells TV Fanatic.

Bloodlines will have “less emphasis on angels and demons and things like that, because those are not really the core concept in Supernatural, the mother ship,” Dabb adds.

The writers never considered Bloodlines a replacement for the parent series, which has been renewed for a tenth season. Rather, “it’s like the universe can exist alongside it but it’s in no way meant to come in and steal Supernatural‘s thunder.”

Unlike Supernatural, which takes place in a different city each week, Bloodlines is set to take place in Chicago. The Midwestern city appealed to the writers because “Chicago has a great history with the mob stuff like Capone but, also, Chicago’s really full of cult history, you now, a darker history.”

Similar to the parent series, though, Bloodlines is set to focus on family, both blood and chosen. “[Y]ou’ve got the five families; you’ve got the werewolf family and the shape shifter family, kind of our two big ones, and then looking at the fun of it is all the family dynamics,” Dabb explains.

“And also, the dynamics between the families, there are grudges and bad blood and very Hatfield and McCoy type stuff and things like that, so it’s offering up a lot of possibilities.”

As for the rules of the new world, “[W]hat’s been established from Supernatural is going to be kind of our governing force,” Dabb says. “Where we feel we have a lot of room for kind of building and a kind of experimenting are in the monster dynamics for the characters, so even if they are a monster, you’ll know where they’re coming from.”

As for potential crossovers with the parent series, Dabb thinks it’s more likely to see some supporting characters pass through Chicago than the Winchesters. “There are characters like Castiel, Crowley, Garth, Jody Mills, people who are from the Supernatural world that I think could be passing through Chicago” and stay for the span of a few episodes.

Dabb also previews that Bloodlines, if it is picked up, will be “more heavily mythologized than Supernatural is, certainly more than Supernatural was in the beginning.”

While “every episode will have an event or a case or something Ennis is working or something David is working from his side,” Dabb says, “we’re going to be focused a lot more on subplots that can carry over from week to week,” though he hopes to have some standalone episodes as well.

Supernatural season 9, episode 20, “Bloodlines,” airs Tuesday, April 29 at 9:00 p.m. ET on The CW.