The next episode of "Grimm" will be the 100^th of the beloved fantasy series. This means that this milestone will make this episode bigger and more intense. From what has already been seen and said about the "Grimm" season 5 episode, it looks like NBC will indeed deliver.

The episode is called "Into the Schwarzwald" and it sees Nick and Monroe's dangerous search for the Seven Keys in the Black Forest in Germany come to an end. At long last, they have finally found the means to access the long-lost treasure but that is not the end of the story.

Fans will remember that before the duo found their way to the precious pieces that will ultimately allow them to unlock the carefully kept secret, lots of creatures were doing everything in their power to stop the two from meddling. Such happened in the previous "Grimm" season 5 episode and will happen again in "Into the Schwarzwald."

Various forces hope to keep this secret permanently buried. But with all the keys now in the hands of Nick and Monroe, Wesen groups believe that the detectives are now mere collateral damage to the successful concealment of this important secret.

Wesens will be out to get them in the next "Grimm" season 5, which means that their success, which Monroe may have marvelled about too early as seen in the promo, will not taste as sweet as they hoped it would despite the fact that they were the only ones to ever get this far in the search.

Meanwhile, as chaos brews in Germany, the same thing is cooking up in Portland. There's a new assassin in town that Hank and Wu go will go after. Captain Renard is helping out since this murderer made a casualty out of the mayoral candidate he has been supporting.

However, this killer assassin also has Eve as his pursuer, which means that he is someone from Black Claw. Lastly, Rosalee will be fighting her own battle in this "Grimm" season 5 episode as well, seeing that she has an unexpected visitor from her past.

"Grimm" season 5 episode 12 "Into the Schwarzwald" airs March 11 at 9 p.m. ET on NBC.