After waiting for almost 4 months, fans will finally get to know what happened to Barry Allen, after he voluntary walked into the Speed Force in season 3 finale that aired back in May.

The Flash season 4 premieres this Tuesday (10 October) at 8pm EST and the opening episode is titled The Flash Reborn, wherein the Star Labs team will be seen trying to protect Central City in the Speedster's absence and find a way to bring Barry back.

The official synopsis for episode 1 reads as follows:

With Barry (Grant Gustin) in the speed force, Iris (Candice Patton), Kid Flash (Keiynan Lonsdale), Joe (Jesse L. Martin) and Vibe (Carlos Valdes) have taken over protecting Central City. However, when a powerful armoured villain threatens to level the city if The Flash doesn't appear, Cisco makes a risky decision to break Barry out of the speed force. However, the Barry that comes out isn't the same Barry that went in.

Click here to watch The Flash season 4 live via The CW app. You can also watch the episode online by clicking here (only in the US).

Although Cisco, Caitlin will be successful in bringing Barry back from Speed Force, according to actor Carlos Valdes – who plays Cisco/ Vibe– fans will get to see a different version of the Forensic Scientist.

Valdes told Entertainment Weekly, "Cisco, being the technology genius god that he is, always has a trick up his sleeve. So as far as Barry being trapped in the Speed Force is concerned, he definitely has a plan for that. "

Revealing more about Barry's struggles once he returns from the extra-dimensional energy, the actor revealed, "Barry comes back from the Speed Force, and he's a madman. He's spouting all these crazy, nonsense words and dialogue that just doesn't make any sense, and it's all chopped up from different semblances of conversations."

"As far as the team's skill set is concerned, there's nothing that they can do about this, so episode 1 is basically just about figuring out how to get the Barry that they know and love back. They get him in the physical form, but he's not the same," the actor added of episode 1.