'Grimm' Bosses Tease 100th Episode 'Opens a Lot of New Doors,' 'Nobody's Safe'

Several years and seasons ago, Grimm’s executive producers David Greenwalt and Jim Kouf made a promise to rabid fans gathered at the show’s first San Diego Comic-Con appearance regarding the plot of the 100th episode, a chapter so far off and intangible at the time that they doubted it would ever even come to fruition.

“We thought having Hitler morph into a blutbad might be our last hurrah,” Kouf tells Yahoo TV. “We put the promise aside since then because what are the chances we’d have to answer that question because how many shows get to 100?”

This Friday, however, it is time to pay the piper as “Into the Schwarzwald,” the 100th installment of the series about a Portland cop turned fairytale fighter and monster-slaying Scooby gang, is set to air and the guys behind Grimm assure us they wouldn’t have dreamed of not making good on that long ago plot pledge.

“We promised everybody that if we ever made it to episode 100 we’d explain what the knights’ keys were. We never thought we’d have to answer that question,” Greenwalt says. “We had an idea from the very beginning of what the keys would lead to and unlock, [but] didn’t bother to hash out all the details. And when it started getting closer, we realized we were gonna make it. We started with that original thought, then we threw around a lot of other ideas about what it could be and ultimately came back to the first original idea.”

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The mystery of the seven keys forged by the knights who fought for the seven royal families in the fourth Crusade dates all the way back to the pilot when Aunt Marie warned Nick (David Giuntoli) about his Grimm roots/destiny, told him that monsters were real and living in Rose City, and handed him one of those map-engraved bad boys that supposedly leads to a hidden treasure taken from the raid of Constantinople. They have popped up occasionally since then, giving the gang more pieces of the map, and in recent episodes they thought they’d figured out where it led — an old church in Germany. It was decided that Nick and Monroe (Silas Weir Mitchell) would scuttle off to the Black Forest in search of the unknown relic.

“We knew we wanted to send Nick and Monroe out of the country on this quest together… ,” Kouf explains before Greenwalt jumps in to add, “Because they were our original two guys.” Kouf continues, “And that brought it around full circle. We had been dying to go to Germany from the get go.” (Unfortunately for them and the actors that did not translate into a location shoot as only exteriors were shot in the land of schnitzel and sausage.)

Their journey will come to a successful end in “Schwarzwald” and the tucked-away treasure will be recovered in that hole the characters fell into at the end of the last episode. “Huge surprise. It’s a Volkswagen, a really old one,” Greenwalt jokes. Kouf continues the bit, “And it morphs into Herbie.” Then Greenwalt delivers the punchline, “And everyone figures out we’ve been making a Disney show all along.”

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All kidding aside, they were serious about revealing the spoils of war. “The answer is in real history,” Greenwalt says. “If you know a little bit about the Crusades and Constantinople and what was there, then you could probably figure it out. The answer has been there all along.”

And just as the legend promised, it is a biggie and its locating will have major consequences. Greenwalt teases, “The good thing is the story keeps morphing. What they discover at the end of the 100th episode opens up a lot of new doors and introduces more questions and possibilities so it actually allows us to explore a whole other universe of ideas. There is lots of chaos coming. Nobody is safe.”

Kouf says the ramifications will continue to be felt throughout the rest of the season — they were currently in production on the penultimate episode of Season 5 when they phoned us for the interview last week — and will likely affect the Black Claw uprising storyline. “It is big [what they discover] and, believe it or not, it gets bigger. Bigger and wilder changes occur between 100 and 110. It gets really wild towards the end of the season.”

When asked if Black Claw’s wesen revolution will carry over to next season or be resolved by the finale, Greenwalt would only say “a little bit of both.” He says, while the attacks are happening all over the world, the monster movement has plans for Portland and those plans explain why they took out Renard’s political pal at the rally. “Portland is geographically important in the Pacific Northwest and you just might be right [about Black Claw having plans for Renard].” Kouf adds, “Black Claw’s influence is reaching into more and more areas in their effort to upset the apple cart.”

This admission harkens back to something Kouf declared earlier in the interview, when teasing that Adalind is “going to go through a shocking change,” and now seems like a warning of sorts for multiple characters. “What I find interesting about the show is that nobody is 100 percent good or 100 percent villain and they change over time and depending on the circumstances. They wax and wane through different situations and emotions.”

Greenwalt added, “Everybody is going to wax and wane except maybe Rosalee and Monroe. Everyone has something coming.”

Despite all the cryptic teases, the furthered origin story, and the threat of impending chaos, the producers know that fans, like themselves, love the quirkiness and levity that has long been a part of the show and reassure that it isn’t all serious from here to the finale. There will be prized new-monster-of-the-week episodes and new species of critters.

Greenwalt says, “We will explore the desire for beauty at any cost.” Kouf adds that one revolves around plastic surgery before announcing that he is looking forward to sharing “a great Mexican wrestling episode about La Luchador.”

The “Into the Schwarzwald” episode of Grimm airs Friday, March 11 at 9 p.m. on NBC.