The sci-fi drama's fourth season will conclude with two-part episode 'Brave New World'.
Noble, who plays eccentric scientist Walter Bishop, told Give Me My Remote: "Walter has to face his demons."
He teased: "I'm not going to tell you what the demons are, but he comes... face-to-face with these demons and he's either got to make or break!"
Fringe - which also stars Anna Torv and Joshua Jackson - was recently picked up for a fifth season by Fox. The 13-part final run will see the series reach its landmark 100th episode.
The show continues on Fridays at 9/8c on Fox. In the UK, Fringe airs on Tuesdays at 10pm on Sky1.
> Fringe star Jasika Nicole on alternate world twist
> Robin Williams: 'Fringe role would be amazing'
Watch a trailer for the Fringe finale below: