'Grimm's' 100th-Episode 'Bro-cation' Unlocks the Mystery of the Keys

The mysterious seven keys have been a continuing thread on “Grimm” for the better part of five seasons, and with tonight’s landmark 100th episode, fans finally learn how they fit into the larger mythos of the NBC supernatural drama.

"We'd been promising the keys would come back in the hundredth episode,” executive producer Jim Kouf told SPINOFF during a visit to the show’s Portland, Oregon, set, “so we figured we'd better deliver on that promise. They find out where the keys are."

"Not only do we find the keys,” added executive producer Norberto Barba, “we find out what they open and then that reveals something new and exciting."

In the episode, titled “Into the Schwarzwald,” Nick (David Giuntoli) and Monroe (Silas Weir Mitchell) discover a treasure in Germany that’s been hidden for centuries. Or, as Mitchell teased, “Nick and Monroe will be taking a bro-cation to Germany to figure out where these keys are."

"We get back to our roots in a way,” he said. “There's a lot of Nick and Monroe trying to figure something out together. We're on a quest together. It's really fun."

Of course, the keys are only one aspect of the increasingly complex mythology developed for the series, which blends police drama and supernatural fantasy. "It's a challenge, obviously, because you start with a little bit, and you never know how far you'll be able to go,” Kouf said. “So, we try to allow it to build naturally. A lot of our mythology is based on real history and we're explaining real history in an obtuse way. We take real historical events and reexamine them in another light."

Barba said “Grimm” has consistently presented new obstacles for the producers from episode to episode. “One of them, from Day 1, has always been the tone. We want the comedy,” he said. “There are times when it's very lighthearted and fun, and other times we want to scare the audience. We want to do all that while developing friendships; we need to nurture those. Another challenge is weighing the mythological aspects of the big story with whatever the new Wesen they discover is.”

Over the past 100 episodes, “Grimm” has seen the characters grow, too. “I think Monroe has had a pretty clear voice through the entire series,” Mitchell told SPINOFF, “and the changes that I've gone through have to do with learning the world is a more dangerous place than I would have wanted it to be. Monroe was pulled fully into the Wesen world by Nick and forced to deal with it. If anything's happened, his heart has become a little more cagey, but at the same time it's opened up with Rosalee. I've become a more careful. I've gone through phases of being a badass and phases of being domesticated, and I think that's fun. That's true about life."

While Sasha Roiz said he enjoys that his character Renard still keeps the audience guessing -- “I like that it looks like he might flip sides at any second” -- Russell Hornsby likes how Hank has grown more comfortable with the bizarre world of “Grimm.”

"Hank's embraced his badassery,” he said. “He's OK with being more confident while being a little mercurial. He has a willingness to have fun with the things he runs into and not being afraid of what lurks in the dark. Everybody has different element they bring to the table, and with Hank, it's the element of being cool and a badass."

However, it’s Nick who has undergone the greatest evolution in the series, from learning his birthright as a Grimm in the beginning to experiencing the darkest of dark times in recent seasons.

"I think he's become a determined leader and a man throughout the five years,” Giuntoli said. “A lot has happened to him. He's dealt with a lot of adversity, but he's not really afraid of things."

“Grimm’s” 100th episode, “Into the Schwarzwald,” airs tonight at 9 ET/PT on NBC.

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