This Evil Season 1 Finale Sneak Peek Shows Kristen Tightening Security for Her Daughters

Raising four girls with a mostly absentee husband is hard enough when your go-to babysitter isn't dating the devil's minion, but that's life for Evil's Kristen Bouchard (Katja Herbers). In the CBS drama's Season 1 finale, airing Thursday at 10/9c, Kristen's situation at home gets even more complicated when she stops trusting her mother, Sheryl (Christine Lahti), to watch the kids -- right as an old case resurfaces that could threaten their safety.

In TV Guide's exclusive clip from the season finale, above, Kristen tightens security for Lynn (Brooklyn Shuck), Lila (Skylar Gray), Laura (Dalya Knapp), and Lexis (Maddy Crocco), giving her daughters the peppiest home security talk she can manage while casually explaining that Grandma is going to "take a break" from babysitting duties for a while. Sheryl has been carrying on a covert romance with Leland (Michael Emerson) behind Kristen's back, but the consequences of that affair catch up to her in Thursday's episode.

Still, no matter how poisonous their relationship might be, series co-creators Robert and Michelle King say Leland hasn't bewitched Sheryl -- at least not supernaturally. "You don't need the supernatural to explain the attraction there," Robert told TV Guide. "I think she's in love... Now is it that there's a sexiness that comes with being a demon? Possibly."

"There's something adolescent about [Sheryl] anyway," added Michelle. "And so one senses she's always been about rebellion."

Evil Stars Tell Us If They're Here for a David and Kristen Romance

Sheryl may be exiled from Kristen's home life right now, but not everything Kristen is freaked out about can be fixed with new locks on the doors. The season finale also brings a new case for Kristen and David (Mike Colter) that gets personal for Kristen in unexpected ways, causing her to question one of her daughters' capacity for evil.

The Kings told TV Guide they "adore" the young actresses who bring Kristen's daughters to life, whose nonstop talking over each other is inspired by the creators' own lives. "I'm from a family of seven kids," Robert explained. "It was usually three or four people talking on top of each other, driving our parents crazy, but there's a great energy that comes with that." To keep the girls' dialogue feeling real, their lines are grouped together in the scripts for the actresses to split up and riff on as they go. "I would say two thirds of the lines they're speaking are scripted and one third are ad libs on their part," he added.

The cast previously teased to TV Guide that this season ends on a jaw-dropping final shot. "The last thing that Kristen sees is mind-boggling," said Kurt Fuller, who plays Kristen's therapist, Dr. Boggs. "And I'm very excited for people to see that last thing."

Lahti agreed, adding, "I feel like my character might have to take some responsibility. And maybe Leland. It's really scary, and it's a turn that no one is going to expect."

The Season 1 finale of Evil airs Thursday, Jan. 30 at 10/9c on CBS.