“I’ll Be Back Before Midnight” might be an unfamiliar play to many, and director Lisa Bennett wants to keep it that way.

“You’re not sure who’s who,” Bennett said about the characters in the script. “You’re really unsure — ‘Oh, they’re OK.’ ‘No, they’re not.’ I kind of like that edge-of-your-seat type show, where you can’t identify evil until it’s right there.”

The answers will come starting Friday, when “I’ll Be Back Before Midnight” opens at Trumbull New Theatre for a three-weekend run.

Peter Colley’s play, first produced in 1979, tells the story of a couple who rent a remote cabin. The wife Jan is recovering from a nervous disorder, and the husband Greg believes that getting away will be good for her.

But the eccentric farmer who owns the cabin has a habit of telling gruesome ghost stories, and the arrival of Greg’s strange sister Laura only exacerbates her condition. When dead bodies start appearing and disappearing, is Jan imagining it all or is something more sinister at play?

The cast features Niki Baringer as Jan, Marc Bye as Greg, Molly Cravalho as Laura and Dave Dougherty as the farmer.

On Colley’s website, “I’ll Be Back Before Midnight” is described as a dark comedy as well as a thriller, but Bennett said it would take “a sick mind” to call it a comedy.

“There’s a couple of amusing things in it, a couple of things I get a giggle out of, but no, it’s not a comedy,” Bennett said.

It’s also a play that comes with enough technical challenges that the script comes with a book of instructions offering advice on how to execute them.

“Some of the instructions, it’s like, ‘Well, duh, yeah,’ but a lot of them were very helpful and at least pointed us in the right direction,” she said. “There are things I want to tell you to answer your question, but I don’t want to reveal anything.”

Lighting and sound cues play an important role in setting the mood. Ed Sebben, who’s done many shows at TNT but had to take a hiatus due to work obligations, is handling the lighting and creating the effects needed for a farmhouse with old wiring, and Brent Bunker worked on the sound design with Jackie Shannon operating the sound board during performances.

Bennett described “I’ll Back Before Midnight” as a return to the kind of show she enjoys directing.

“I am really thrilled to be doing a mystery,” she said. “It seems like forever since I did one … With a musical, it’s all thrown out in front of you, whereas there’s more intricacies and more depth to the characters, I believe, in a mystery.”

If you go …

WHAT: “I’ll Be Back Before Midnight”

WHEN: 7:30 p.m. Friday and Saturday through Nov. 22 and 3 p.m. Nov. 16 and 23

WHERE: Trumbull New Theatre, 5883 Youngstown Warren Road, Niles

HOW MUCH: Tickets are $17 for adults and $15 for students and are available online at trumbullnewtheatre.tix.com and by calling the TNT box office 330-652-1103 between 7 and 9 p.m. Monday through Wednesday.