Reese Witherspoon is showing off her serious side!
The just-released trailer for "Wild" finds the 38-year-old actress playing real-life author Cheryl Strayed, a recovering heroin addict from Oregon, in the gritty, emotional film based on Strayed's best-selling memoir.
The character embarks on a treacherous 1,100-mile journey of self-discovery by herself through the mountains of the Pacific Crest Trail, which marks her first major hike.
"Oh my God, what have I done," she says in the clip.
Witherspoon's character comes face-to-face with wild animals and trudges through raging rivers, rocky terrain and snow but also witnesses breathtaking views as she ponders her past mistakes and reminisces about her loved ones.
"What if I forgive myself?" she says. "What if I was sorry?"
"Wild" is adapted for the screen by Nick Hornby ("An Education"), and it also stars Laura Dern ("Enlightened"), Thomas Sadoski ("The Newsroom"), Gaby Hoffmann (Girls), Kevin Rankin ("Dallas Buyers Club") and Michiel Huisman ("Game of Thrones").
The movie hits theaters on December 5 -- are you excited to see it? Sound off!