'Fringe' Season 5 teaser: Walter puts up a fight

The latest teaser for the final season of "Fringe" opens with an idyllic scene in a park, with Peter (Joshua Jackson) wishing his time with Olivia (Anna Torv) would never end.

As we know from the previous promo, though, it does end -- badly -- when a phalanx of Observers comes marching into view and sets sights on Peter and Olivia's daughter, Etta.

The new teaser inflicts further trauma on the Bishops. After a series of quick cuts that shows a giant Observer propaganda poster that reads "The future in order" and an ominous-looking medical lab, we see an Observer standing over Walter (John Noble), who's tied to a chair and bleeding.

"You are fighting much more than I would have thought possible," the Observer tells him. Which sounds like a compliment on paper, but when spoken seems to portend some very bad things ahead for Walter.

"Fringe" premieres Friday, Sept. 28 on FOX. You can see all the season's premieres in Zap2it's fall calendar.