Devil In Ohio's sixth episode opens with Suzanne at the hospital, wondering why Dani didn't call. Well, that's not really shocking considering how Suzanne has ignored her the entire season. When Mae and Peter both arrive, they discover that Jules has vanished. She's with that sketchy boy, as we all know.
Driving alongside Jules, a sketchy man named Noah suddenly slams on the brakes and motions for Jules to get out of the vehicle. She sees all the stars in the sky when he takes her to a remote location and urges her to look up.
Just before returning her home (properly this time! ), he writes "something to remember her by" on her forearm. That is, in fact, the identical A that was on the back of Suzanne's vehicle. He's actually a member of this cult and Mae's brother, as we eventually discover from Mae later.
Lopez prints up the images he took that night and attempts to figure out how the Dodds, the rituals, and the cults are related in this case. They look to be creating some kind of accelerant.
Jules eventually arrives late at night, but when we witness flashes of Suzanne's past, this triggers horrible emotions for her. It transpires that the officer who was attempting to remove her from the tree wasn't really a member of a cult after all. Dennis was Suzanne's stepfather. He was a monster at home, abusing Suzanne's mother, which eventually led to Suzanne fleeing, we learn as Suzanne goes to therapy and spills everything.
Suzanne's wrist scars were caused when she was chained to a radiator and left on. Despite her mother's arrival to soothe her, a flash at the episode's end shows she let the abuse continue while trying to calm Dennis down.