Grimm's 100th episode finally has a title.

'Grimm' Season 5 Spoilers: Rosalee Kidnapped! Nick Takes On 'The Lost Boys'

Set to air as the 12th installment of season 5, the milestone hour will begin filming in early November. As the cast and crew prepares to solve the Seven Key mystery once and for all, executive producer Norbert Barba updated fans on the highly anticipated episode.

For those whose German is rusty, the Schwarzwald is the proper name for the anglicized Black Forest. As viewers know, this is where Monroe (Silas Weir Mitchell) and Nick (David Giuntoli) believe the Seven Keys lead when fully assembled.

'Grimm' Season 5 Premiere: Adalind Goes Into Labor! Sneak Peek For 'The Grimm Identity'

Grimm's foray back into the atlantean puzzle won't be a one episode affair, however. The wheels will begin to turn with episode 10, "The Map of the Seven Knights," and will continue to ramp up during episode 11, which is titled "Key Move."

How will the Keys come together? Nick currently holds two pieces of the puzzle, but one key remains unaccounted for while the other four lay in the hands of the Royals.

While we patiently wait for answers, you can check out a preview for the season 5 premiere below.

Grimm will return to NBC this Friday at 10 p.m. ET.

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