Things will get intense on Friday's all-new episode of "Grimm" as Nick attempts to help Juliette by giving her Adalind's Hexenbiest suppression potion while investigating a Jack the Ripper copycat on the loose.

Earlier this season, Nick slept with Adalind while she was pretending to be his girlfriend, Juliette. Although the one-night-stand helped Nick regain his powers as a Grimm, it caused serious repercussions for Juliette, who was transformed into an evil and super powerful hexenbiest. Since then, Juliette has been embracing her inner beast and rage.

On the next episode, which is titled "You Don't Know About Jack," Captain Renard will suspect that a killer who committed a string of homicides in Portland has been inspired by the notorious serial killer Jack the Ripper.

Meanwhile, Adalind will convince Nick that she has a cure that will help tame the hexenbiest inside of Juliette. However, in order to make the potion, they will need to solicit help from Monroe and Rosalee.

A sneak peek reveals that Adalind will test the potion, herself, to see if it will work on Juliette.

In addition, a preview video shows that Nick will go after Juliette for setting his late Aunt Marie's trailer on fire. As a result, all of the documentation of ancestral, ancient Grimm lore and weaponry was destroyed along with the book of drawings of Wesen and reports on how to kill them, notes Oregon Live.

During an interview with TVLine, show creator David Greenwalt described Juliette as being "out of control," and compared her to "a baby with a bottle and a gun." She also may ended up hooking up with Captain Renard again. "They might make hate at some point," Greenwalt joked.

He also teased that Trubel will return, "but you don't really know it's her." He added that "Baby Diana will be seen, but not in the same form as before."

Co-creator James Kouf also opened up about the Season 4 finale, which will air on May 15. He teased that Nick will come across a discovery that will cause him to seek revenge against the Royals. Meanwhile, Juliette will continue on a pathway of destruction after she rejects help from Monroe and Rosalee.

According to CarterMatt, the synopsis for Friday's new episode reads as follows:

"A string of homicides have the press asking Captain Renard (Sasha Roiz) if a Jack the Ripper copycat has arrived in Portland. While dealing with the investigation, Nick (David Giuntoli), Hank (Russell Hornsby), Monroe (Silas Weir Mitchell) and Wu (Reggie Lee) deal with a situation they never expected. Meanwhile, Adalind (Claire Coffee) and Rosalee (Bree Turner) must work together on a last ditch attempt to fix Juliette's (Bitsie Tulloch) condition."

"Grimm" Season 4, Episode 20, "You Don't Know About Jack," airs on Friday, May 1, at 8 p.m. EST on NBC.

Watch preview videos below.