"Grimm" Season 4, Episode 9 airs Jan. 9 on NBC, according to reports. The fall finale left viewers shocked with the latest twist, which could dramatically change the dynamics of the show. Bitsie Tulloch talks about the new Hexenbiest in town. Meanwhile, there is no news yet on Trubel (Jacqueline Toboni).

Spoiler alert: This update contains Grimm Season 4 spoilers. A new Wesen has emerged. Read at your own risk.

Grimm Season 4, Episode 9 is called "Wesenrein," Tulloch teased with a script photo she posted on Twitter.

Tulloch's character Juliette delivers the big shocker in the fall finale of Grimm Season 4 (Episode 8). After successfully helping Nick (David Giuntoli) become a Grimm again, Juliette becomes something else. Just like Adalind (Claire Coffee), the woman she hates the most, Juliette has become a Wesen, specifically, a Hexenbiest.

Nick's longtime girlfriend is not an outsider anymore. But Juliette will fight desperately to get her old self back, Bitsie Tulloch told Zap2It.

"[Juliette is] going to try to hide [her transformation to a Hexenbiest] from [Nick] while she figures out how to correct it," Tulloch said, noting that Juliette is "scared." The next Grimm Season 4 episode is not likely to show Juliette talking to Monroe (Silas Weir Mitchell) and Rosalee (Bree Turner) about this development, either.

"I think she's not going to turn to her closest friends or Nick for help with this one. She's too scared of how they will react," Tulloch said.

Juliette's transformation occurs just when Sergeant Wu (Reggie Lee) has seen the real answer he has been looking for since seeing an aswang in Grimm Season 3. David Giuntoli dishes his thoughts on this update.

"Reggie's been playing it like he's got an eye on us, on Hank (Russell Hornsby) and myself a little bit. But he is tentatively accepting this as OK. This is all making sense," Giuntoli told TVLine in an interview.

Both Tulloch and Giuntoli teased about a must-watch Hexenbiest battle sometime in the Grimm (Season 4) future. Both actors also said there is no update yet on when Trubel will return to Portland. Tulloch has seen the script up to Grimm Season 4, Episode 14, and still no Trubel.

For his part, Giuntoli has brought up a spin-off idea for Trubel. Grimm showrunner and co-creator David Greenwalt has discussed the same possibility, too.

Grimm Season 4, Episode 9, was written by Thomas Ian Griffith and directed by Hanelle Culpepper. The dark fantasy series airs Fridays on NBC.

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