Even people who make theater in unexpected places aren't always sure they love the idea. Ask Frank Theatre's Wendy Knox, who directed "A," a play by Suzan-Lori Parks, at the then-decrepit Pillsbury "A" Mill on the Minneapolis riverfront in 2004.

"We were still figuring out the heat there," Knox recalled of one rehearsal. "We had these giant blowtorches pointed toward the stage that were, like, 6 feet tall. They kept the actors warm, but if you sat behind them, where I was, you couldn't hear a thing. I was getting really sick and I couldn't hear the show and I thought, 'This is one of the stupidest things I've ever done.' "

And yet she's doing it again. When her staging of "The Visit" opens Friday at the Minnesota Transportation Museum at the Jackson Street Roundhouse in St. Paul, it will add to Frank Theatre's 30-year history of unexpectedness.

Theater performed outside actual theaters is often called environmental or site-specific — Knox likes the term "rough spaces" — and Twin Cities troupes seem to be doing more of it.

"It's challenging, but it's so thrilling and it becomes so much fun to figure out: How do you fit this in here? A rough space brings in a whole level of fun," said Knox, whose experiences at the mill, a former Rainbow Foods (2016's "The Good Person of Setzuan") and a former Sears (2003's "The Cradle Will Rock") solidified a few things.

"The three questions I always ask now when we go to look at a space are: Is there heat? Is there power? Is there a toilet?" Knox said. (She could add: "Is there a rat decomposing in that toilet?" because there was one at the mill.) "I'm not asking too much, am I?"

Mixed Blood Theatre will offer none of those things next May for its world premiere of "Autonomy," which asks whether the automobile or theater is a greater art form. Audiences will view the show from their cars, driving around a vast space. (Mixed Blood is negotiating with the ­RiverCentre parking ramp in St. Paul.)

Having done the baseball-themed "Safe at Home" at CHS Field last year, artistic director Jack Reuler is a believer in theater-less theater. "In time, as our options for share of minds and dollars change, these kinds of shows will not be a novelty. They'll be the way theater artists choose to present their work," he said. "Sometimes theaters get in the way of theater."

Bringing 'a strong flavor to the broth'

Knox said she doesn't know if site-specific work is the future of theater, but she agrees it may attract folks who don't put plays at the top of their entertainment lists.

"It becomes this cool event, although I know there are people who go, 'I dunno,' if it's in unknown space," she said. "That's not necessarily a plus for everyone."

She suspects the Transportation Museum, which includes a working railroad roundhouse and a blacksmith's shop, will be a plus for "The Visit." The psychological drama, in which a mystery woman (Katherine Ferrand) returns to the town where she was wronged as a girl, begins in a railroad station. Knox learned of the museum after an e-mail to Frank board members hit pay dirt.

"This museum brings a strong flavor to the broth," she said. "The existing stuff — the train cars, these heaps of old parts — all becomes the backdrop and the whole play takes place in front of a locomotive. When we saw it the first time, Joe Stanley, who is doing the sets, and everybody else thought it was cool, so we all started thinking, 'This could go there' and, 'We could use that space for this.' "

Knox said it's crucial to be inspired by the site: not to just stick a play in a warehouse, but to make choices based on the building's character. Rainbow's loading dock became a crucial element of "Good Person."

"The museum definitely puts some confinements on the production. But the bonus will be all the stuff the space brings to it," said Knox, who is reminded of a bystander she saw during rehearsals at the "A" Mill.

"I asked if I could help him with something," says Knox. "I think he was 92, and he said, 'I used to work here before the war. My station was right over there.' And he started crying. It was so sweet. It was the history of the place.

"There's a little 'woo-woo' in here, I guess, but it brings in a positive energy and makes the spirits happy when you work in concert with whatever ghosts are there."

To the manor born

Ghosts are exactly what director Joe Hendren wants next month for a sold-out adaptation of Shirley Jackson's horror novel "The Haunting of Hill House" at what you could think of as the most lavish set in St. Paul: the James J. Hill House (no relation between the Hills).

This month Hendren directed the courtroom drama "Minnesota's Coldest Case" in St. Paul's Landmark Center, a former federal courthouse. He sees the city's largest house as the perfect place for a play about a ghostly manor.

The Hill House presents restrictions: The woodwork is hands-off, and a show staged there a couple of years ago had to lower its volume because the speakers made the chandeliers shake. But the hope is that the history of the place becomes the history of the play.

It's a concept that is far from new.

"Historically, you have all of these traveling troupes that would go from town to town with a wagon and set up in the town square, doing theater wherever it suited them," said Hendren, who also has staged work at Fort Snelling and who recently became artistic director of Minneapolis Musical Theatre, which staged "High Fidelity," a musical set in a record shop, at Electric Fetus in Minneapolis this year. "Maybe we've come full circle?"

Bob Neu has directed at the Hill House, too, including "Marriage of Figaro" in 2016. In addition to the knockout "set," he likes its intimacy. "It's so extraordinary for the audience to be so close, to see that energy, to feel the breath coming out," said Neu, who will stage two Skylark Opera shows next year in nontraditional spaces, along with site-specific works in Seattle and Orlando.

Neu likes regular theaters, too, but said they can create "a distancing aspect. It maybe doesn't grab your heart the way it would if somebody right next to you were having a big moment of grief or joy. When you can actually breathe with the performer, I think it takes you to a new realm."

Directors agree that site-specific work requires special performers who can adjust their acting for intimate venues and roll with the idea that surprises happen when you invite audience members into your playing space.

Knox's colleagues have learned to expect the unexpected, especially the "Good Person" actors who signed on to do the show at Minneapolis' Ritz Theater, which fell through at the last minute.

"This is one of my favorite Frank Theatre moments ever," Knox said. "It was the first read-through, and I had already cast the show, with a lot of people I hadn't worked with before. I said, 'OK, you guys. I know I told you we were doing it at the Ritz, but, actually, we're doing it at Rainbow Foods.' The blank stares I got! It was like, 'What are you getting us into?' "

Knox said she's indebted to the collaborators who have been willing to join her in rough spaces, where they may encounter oil, grease, soot and the occasional dead bird. "It takes a certain adventurous spirit on the part of the audience, finding these places," she said. "Some might not be up for it, but Frank's audience is generally game.

"We've been dragging these people around for 30 years."

Chris Hewitt • 612-673-4367 • Twitter: @HewittStrib