Flash season 4
Grant Gustin as Barry Allen in The Flash The CW

When The Flash season 4 premieres, Barry Allen would have spent six months inside Speed Force, while Iris West, Cisco Ramon and Wally West would have taken the reins of Star Labs and become the saviours of the city.

Grant Gustin, who plays the Scarlet Speedster, has revealed that fans will see a different Barry, following his return from Speed Force at SDCC. He spoke about where his character is when we catch up with him in season 4. "For Barry it hasn't really been six months. In the Speed Force time is kind nonlinear, and I think this experience in the speed force has been different for him."

The Speedster will have an "awakening" when he returns from the energy prison. "We've seen him go into the Speed Force before, and had the Speed Force embody different people in his life and kind of teach him the lesson he needs to learn at this point. But this time he sacrificed himself to stabilize it, so I think he's been kind of on his own and he's been experiencing his entire life from start to finish again and again and again," Gustin said.

"So I think when he comes out, he's kind of had this awakening and understanding of things that he's never had before, and he's able to let go of a lot of things," the actor added.

Barry will be "confused and jumbled" upon his return according to the actor. "But initially when we see him, he's also kind of confused and jumbled and it's been a lot, so he's not really himself. We'll see the toll it took on him, initially, when he comes out. He's kind of jumbled initially, after experiencing so many things in such a condensed amount of time over and over and over again. It takes a toll on your brain, you know? So it's not really Barry when he first comes out and I got to have fun with that as an actor."

In Barry's absence, Kid Flash and Vibe will pick up Barry's mantle, according to actor Carlos Valdes. The actor who plays Cisco explained, "I can tell you straight up, It's not good. Six months have passed since the disappearance of Barry Allen and the team is sort of clutching at straws to keep the city together, and though Kid Flash and Vibe are out in the field doing their thing and trying to keep it together.

"There is a unanimous feeling amongst the remaining members that it's just not the same without Barry. We cannot keep the villains at bay with the same efficiency that he used to. So in light of that, Cisco does whatever it takes to get his friends back," he added.