'Grimm' season 6 news: Final season pits Nick and Renard in explosive final battle

"Grimm" is all set to wrap things up, and the creative minds behind it promise to leave no stones unturned when NBC's popular occult police procedural series takes its final bow.

The upcoming sixth and final season of "Grimm" will run for 13 episodes and will essentially be about Nick (David Giuntoli) and Renard (Sasha Roiz) trying to bring each other down. In a new featurette posted on the show's official YouTube channel, actor Roiz shares that now that both Black Claw and Hadrian's Wall have both been decimated, season 6 will really be about the fight between Nick and Renard's factions, which actor Giuntoli describes as a "battle royale."

"Nick and the Captain, their relationship has been filled with tension and distrust from the beginning," Roiz said. It seems that despite Renard's previous efforts to keep Nick alive, even thwarting off threats coming from his own family of Royals, the police captain and newly elected mayor of Portland may well have turned to the dark side and is now very determined to eliminate Nick himself.

However, could this really be the Captain's real end game? What caused the sudden change of heart? Has he always harbored a secret desire to take the Grimm down himself, and has only kept him alive so long as Nick served a purpose in bringing him to the position of power he is in right now? Will this desire for power ultimately bring him to his end?

Executive producer David Greenwalt also shared that the show's final season will also be addressing a couple of "very large questions" that have never been dealt with in the show's five-year run. What could these unanswered issues be? Could it be something recent like the magic stick, or is it something more encompassing like an underlying mystery that has always been around, but was never directly addressed?

The newest trailer for the upcoming season also hints on Diana's (Hannah R. Loyd) involvement in the upcoming war between her father, Renard, and her mother's babydaddy, Nick. Whose side will she ultimately take, and will her involvement shift things around for the better or for the worst?

"Grimm" season 6 premieres on Friday, Jan. 6, at 8 p.m. EST on NBC.