Inside one of the vast Northwest Portland warehouse spaces used as shooting stages for "Grimm," Sasha Roiz is in bed.



Temporary, low-rise walls create a sort of cubicle effect, as Roiz, in character as Portland Police Captain Sean Renard, is surprised by a visitor to his bedroom.



Co-star Bitsie Tulloch, who plays Juliette Silverton, and Roiz rehearse their lines. The director calls for the camera to roll, and the actors play the scene. Juliette bursts into Renard's room, and the two have a heated exchange. They go through the scene a few more times, until the director calls cut, and Roiz and Tulloch take a break.



Onscreen life is one stressful thing after another for the "Grimm" characters, who contend with supernatural creatures, a power-mad European royal family, ancient keys, and Portland's ever-unpredictable weather.



But on an early February visit to the "Grimm" set, the stars are all smiles. There's no mystery about why: just the day before, the "Grimm" cast and crew got the good news that NBC renewed the set and filmed-in-Portland for a fifth season.



On this day, "Grimm" life is good.



"We're so excited," Tulloch says. "We didn't expect to get the renewal announcement this early."



"Grimm" premiered in 2011, and while other, higher-profile NBC hour-long dramas that launched around that same time are history, "Grimm" has been a solid performer for NBC, reaching an average of 7.2 million viewers per episode.



"We were always the little show that could," Tulloch says. "It's not like we were one of the shows that got heavy promotion."



But "Grimm" benefits from a fan base that loves its stories about Nick Burkhardt (David Giuntoli), a Portland homicide cop. Nick is also a Grimm, descended from a long line of criminal profilers -- including the Brothers Grimm -- who can see Wesen, or supernatural creatures, hiding beneath their ordinary human appearance.



The combination of fantasy elements, an overarching mythology about the history of Grimms and Wesen, case-of-the-week procedurals, and an ensemble cast with chemistry to burn, have won "Grimm" a following around the world. In the U.S., reruns air in syndication on TNT.



"One of the best things about being a genre show is that the fans are so loyal," says Tulloch.



More mayhem on the way



But before getting into gear for a fifth season, the "Grimm" cast and crew are hard at work in Portland wrapping up Season 4, which has thrown even more wild plot twists into the mix.



When Season 4 began, for example, Tulloch's character, Juliette, was still human. But after various machinations to help her boyfriend Nick regain his Grimm powers, Juliette has turned into a Hexenbiest, a fearsome Wesen who has a witch's mighty powers.



When last we saw the gang, in the Feb. 13 episode, Juliette had a fierce battle with Adalind (Claire Coffee), who learned her fellow Hexenbiest had powers greater than her own, and skedaddled away in a hurry.



"Grimm" returns with new episodes on Friday, March 20, at a new time, 8 p.m.



Even more shocking than the Juliette-Adalind showdown was Juliette revealing her new, Wesen self to her boyfriend, Nick, who recoiled at the sign of Juliette morphed into her Hexenbiest form.



Having uncontrolled Hexenbiest powers may be terrifying for Juliette, but it's the kind of bold storytelling choice that keeps "Grimm" fresh.



"As an actress, this is really, really fun," says Tulloch. "Juliette is a potent force. But right now, she's really just scared of hurting Nick. I don't think she realizes how powerful she is, and that's going to be played out over the course of the rest of the season."



Roiz points out that Renard, who is half Wesen himself, has his own issues about dealing with Juliette in her altered state. His mother is a Hexenbiest, and the normally cool and collected captain makes questionable choices when these witchy women enter his life.



"There's some sort of magical component to these Hexenbiest, they're very sexual, they're like sirens. For someone like Renard, who's derived from that lineage, it's very powerful for him. I think it's starting to happen with Juliette, as well. He can't make sensible decisions when she's around."



The rest of Season 4 promises more stress for Renard, Roiz says. A new member of the Royal family -- which represents the other side of Renard's parentage, and has a complicated relationship with Grimms -- appears. Adalind is still determined to find where Nick's mother -- also a Grimm -- has taken her baby, Diana, which involves Renard, too, since he's Diana's father.



And then there are those bleeding bullet wounds, ominous souvenirs left over from when Renard was shot and died, only to be magically brought back to life by his mother.



"He's got a lot on his plate," Roiz says, with wry understatement. "It's going to be a very dark transition for him. His brush with death certainly has brought back something."



With all this going on, just how does Renard also do his job as a Portland Police captain?



"Don't bring logic into this," Roiz jokes. "Otherwise, the whole thing will unravel."



Roiz does wonder what a Captain Renard performance review might be like. "Can you imagine? I mean, we had that episode where we have 20 people in a hate group, and half of them are dead. It's like, 'Just trust me, they were bad. No need to look into this any further!'"



Settling into Portland



At another corner of the soundstage, Giuntoli sits in the set that's the house Nick and Juliette share. The relationship has extended beyond the show, as Giuntoli and Tulloch are now an offscreen couple, as well.



"It was a very deep scene study that turned into an actual relationship," Giuntoli says.



Their real-life dating hasn't affected their work on "Grimm," Giuntoli says. "No, when you come in, it's just very businesslike on set. We dated on the show for years, and we did a movie prior to 'Grimm,' and we had to do bedroom scenes, and kisses and things. But when we actually had our first kiss, it was very nerve-wracking."



Like many of their castmates, Giuntoli says he and Tulloch are becoming true Portlanders.



"If a real Portlander is a person who thinks they've been here forever, and gets angry when new people show up, then yes, I'm a Portlander," Giuntoli says, with a grin. "All these new people showing up, who do they think they are?"



He and Tulloch have been enjoying hanging out in Portland while filming, Giuntoli adds. "She's kind of like the Trail Blazers super fan girl. I'll tag along for those, and I love that."



When filming, Giuntoli says, the "Grimm" crew and cast try to be aware "that we are a visitor to the a neighborhood. We're trying to keep Portland happy, because you guys have been so good to us."



Claire Coffee, who's wearing a coat that sort of conceals her real-life pregnancy, agrees that she's got that Portland feeling. "I think I have enough coffee coursing through my veins at this point to qualify for Oregonian status," she says.



Bree Turner, who plays Rosalee Calvert, the expert apothecary who's married to her fellow Wesen, Monroe (Silas Weir Mitchell) and whips up magical potions in her spice shop, is also feeling at home in Portland.



"I don't go back to L.A. at all anymore," says Turner. "We bought a place up here, which just made sense in my situation, with a family of four." Rather than flying back and forth from Los Angeles to Portland, Turner says, "We made the decision to make this our home. It's been way better for my family. I'm able to enjoy work more, because I'm totally present."



Mitchell, whose Monroe character -- a Blutbad Wesen who's sworn off his more wolflike ways -- is a fan favorite, credits Portland for influencing the tone of "Grimm."



Mitchell made a cameo appearance last season on "Portlandia," the IFC filmed-in-Portland series.



"The Portlandness of Portland seeps into both shows," Mitchell says of "Grimm" and "Portlandia."



"Obviously, 'Portlandia' is about that," he adds, "but there's a sense of humor in our show that isn't out of place on 'Portlandia.' And I think that's a tribute to the city's identity. Shows that are so utterly different have the sense of humor that is Portland's. There's a serious whimsy to Portland, and that's a really unique flavor. Portland has an earnest iconoclasm that, to my mind, is unique. I love that about this place."



The "Grimm" actors are also becoming more entwined with Portland culture.



Mitchell and Roiz will be acting together in the play "Three Days of Rain," at Portland Center Stage, which has previews from May 17-21 and opens on May 22.



Roiz was also a guiding force behind getting his fellow "Grimm" actors involved in visiting patients and families at OHSU's Doernbecher Children's Hospital, and raising funds for the "Grimmster Endowment," which aids families who face uncompensated costs associated with care at Doernbecher.



Russell Hornsby, who plays Nick's Portland Police partner, Hank Griffin, will play Stanley Kowalski in a Portland Center Stage production of "A Streetcar Named Desire," in the 2016 season. Hornsby also has worked with Portland students in the August Wilson Monologue Competition, which helps high school-age actors gain insights into the vision of August Wilson, the great African American playwright.



"Because of this job," Hornsby says, "this security, and knowing we'll be here another year, my life has gotten less about me." Acting can be a career that makes you self-absorbed, Hornsby adds. He's taken the opportunity to work with students, "because you know the financial side is fine, so you can not be so selfish. You can think about other things."



Reggie Lee, who plays Sgt. Drew Wu, the Portland Police officer who has only recently been filled in on the world of Wesen and Grimms, has a delicious link to Portland.



Pip's Original Doughnuts, on Northeast Fremont Street, has created "The Dirty Wu," a culinary creation inspired by Lee and his "Grimm" character. The confection combines a hot cinnamon sugar mini-doughnut, warm Nutella, raw honey, and sea salt.



On the set, Lee is dispensing some "Dirty Wu" doughnuts to visitors, and they're a big hit.



"The owner of Pip's gave me the prototype for a 'Dirty Wu' candle," Lee says. "This is like the Oscar," he jokes, indicating a box of doughnuts." Pointing to the candle, he adds, "And this is the Emmy!"



Lee says that working in Portland is "a whole big lovefest. I have a feeling Portland will be in my life forever."



-- Kristi Turnquist



kturnquist@oregonian.com

503-221-8227

@Kristiturnquist