Eve (Bitsie Tulloch) and Nick (David Giuntoli) enter a mysterious portal in the upcoming episode of NBC's "Grimm" season 6.

Titled "Where the Wild Things Were," this week's episode will see how a mysterious portal leads to an unexpected journey. According to the official synopsis, Eve finds herself in an unfamiliar territory after embarking on a new mission. When the team discovers what she did, Nick finds a way to join her in taking down the strange force in the mirror. Elsewhere in the hour, an uneasy alliance is forged when Capt. Renard (Sasha Roiz) is brought in to help. He later discovers that everything that's been happening may be tied to the person he cares for the most, his daughter Diana (guest star Hannah R. Loyd).

Cartermatt notes that Friday's episode title is a reference to "Where the Wild Things Are," a classic children's picture book by writer and illustrator Maurice Sendak. Published in 1963, the book is about Max — a young boy who is transported to a mysterious island inhabited by beasts called "Wild Things." Max later befriends the creatures and becomes their king, until he decides to come back home after realizing that he's no longer happy being there.

As announced, "Grimm" is now on its last season. Executive producer Jim Kouf recently caught up with Yahoo! TV and he admitted that like most fans, he was also disappointed over the show's cancellation.

"We are disappointed that it is coming to a close [but] 5 1/2 seasons were all they wanted," the EP explained. "We were only done because NBC was done. If NBC said 'more,' we'd obviously do more. If [fan petitions worked and] Netflix said, 'We'd do more episodes,' we'd sure be interested in doing it."

Additionally, Kouf teased that the March 31 finale has an open-ended conclusion in case other networks or streaming services decide to pick up the show.

The sixth and final season of "Grimm" airs every Friday at 8 p.m. EDT on NBC.