The finale saw him taking Jay Garrick's (John Wesley Shipp) place in the Speed Force and rather than endless torment, he'll finally find some peace. "He's able to just let go a lot of the things he feels guilty about, a lot of the hardship he's had to deal with," Gustin tells TV Guide.
Those hardships include losing his close friend Caitlin Snow (Danielle Panabaker) to her alter ego Killer Frost and realizing the bad guy trying to kill his fiancé was actually his future self. "Not only was he the big bad towards the end of the season, but he kinda set everything in motion that was bad news last year," he added. "So hopefully, not only for Barry but for the viewers...for Team Flash, there could be kind of a forgiveness and we could move on from all of the drama that happened last year."
While the CW bosses have promised a more light-hearted season, it doesn't look like everyone will be so quick to forgive Barry. There's still the matter of Iris West (Candice Patton), who isn't too happy about him leaving without consulting her first. "She's forced to deal with that anger and resentment and abandonment by kind of focusing on protecting Central City...We're seeing a very different Iris, almost a very hardened Iris," Patton explained.
Before they work things out, Team Flash will first have to figure out how to get him out of the Speed Force.
Watch them try when Season 4 of The Flash premieres Oct. 10 at 8/7c on the CW.
(Full disclosure: TVGuide.com is owned by CBS, one of the CW's parent companies. )