In the anticipation of the fourth season premiere of "The Flash," the CW recently released a promo trailer. Only over 30 seconds long, the latest promo gives fans a little sneak peek on what to expect in the newest season of the popular television series, which features Barry Allen (Grant Gustin) apparently back from his stint in the speed force prison.

The promo is titled "Hero Reborn" and based on the trailer, it seems fans will get to see a somewhat different side of Barry, as he just spent months locked up in prison after sacrificing himself in the season 3 finale. He looks somewhat disheveled, his face covered in a beard, and looks brooding and quite unlike the usual Barry – who is always fun and energetic.

According to the showrunners, months have passed between the season 3 finale and the season 4 premiere, which meant Barry spent a pretty long time in prison. "It's obviously no great surprise that The Flash will continue to be a part of the TV show called The Flash! But the circumstances of his return, and what he's like when he comes back from this experiences is part of the fun and surprise of the season premiere," said executive producer Andrew Kreisberg in an interview with Syfy.

The latest promo also showed Barry reuniting with his STAR Labs friends and love of his life, Iris West (Candice Patton), but the reunion looked wrong and awry. Also, a new villain will make its way to Central City by the name of "The Thinker" (Neil Sandilands). Team Flash will surely get their hands full on this one, as the CW dubbed their impending battle as "the world's fastest man versus the world's fastest mind".

Meanwhile, a new character will not be returning as a series regular in "The Flash" season 4. According to TV Line, Julian Albert (Tom Felton), who was first seen in season 3, will not be seen in the new season. His absence from the show will apparently be explained in the fourth season, and according to showrunner Todd Helbing, there is no guarantee that his absence is permanent.

"There's always the chance that we can see anybody on this show return. We've had a lot of characters come and go for various reasons, and I don't think this will be any different," he said.

"The Flash" season 4 will premiere on Tuesday, Oct. 10 at 8 p.m. EDT on the CW.