"Grimm" is having quite a successful run as it is currently in its fifth season and still going in the ratings game. As the show is gearing up for its 100th episode, actor David Giuntoli spoke with Collider about hitting the triple-digit milestone, saying that luck was a huge factor in the show's longevity.

"There's no amount of hard work and talent that can make something last a hundred episodes, there's a huge amount of luck involved, you need that work and talent, but luck seems the bigger factor, so color me grateful," said Giuntoli.

The show's 100th episode will be the 12th episode of season 5 titled "Into The Schwarzwald." Though the cast and crew havee been keeping mum about the episode, Moviepilot reports that show creator Jim Kouf said that the 100th episode of "Grimm" will finally reveal what the Seven Keys are and possibly even reveal the mysterious treasure that the Keys will unlock.

Back in season one, Nick's (Giuntoli) aunt, Marie Kessler (Kate Burton) gave him one of the keys. Throughout the show's run, bits and pieces of information about the Seven Keys were revealed, such as the fact that the keys belonged to seven knights—the ancestors of the current Grimms—who worked for the seven Royal families back in the 12th century.

During the Fourth Crusade in Constantinople, the knights got their hands on a powerful treasure which they decided to keep for themselves, and they hid the treasure and made a map printed across the sides of all the Seven Keys. Throughout the passage of time the keys were lost, but Nick now has two of them, while the Royal families have four of the keys.

On Oct. 29, executive producer and director Norberto Barba took to Twitter to inform Grimmers that they have "started prep" on the 100th episode. The episode began filming on Nov. 10, and it was reported that "Into the Schwarzwald" will see Nick and Monroe (Silas Weir Mitchell) going on a road trip to find the keys. The milestone episode will air on March 4, 2016.

"Grimm" airs Fridays at 9 p.m. on NBC.