In The Flash midseason finale, "The Man In the Yellow Suit", fans finally learned that none other than Harrison Wells (Tom Cavanagh) was the Reverse Flash, the man responsible for the death of Barry Allen's (Grant Gustin) mother. While it was quite a shocking reveal last month, Grant Gustin himself revealed in a new interview with Entertainment Weekly that, when the show returns tomorrow night with "Revenge of the Rogues", Barry still trusts his mentor Wells, while teasing a major Reverse Flash twist that will come at the end of Season 1.

"Barry is still defending Wells and still trusting of Wells at this point. There's a big twist that even surprised me. I've seen all the predictions online. No one has predicted the big twist that's coming at the end of this season."
RELATED: The Flash Has Officially Wrapped Production

The actor also teased new details about "Revenge of the Rogues", and that Barry is trying to increase his speed to match Reverse Flash.

"He's trying to get faster and not just straight up speed, but his agility and maneuvering within it and what he can do with this speed. He has a bar set. He has to be at least as fast as the Reverse Flash. That's what he wants to focus on, but as per usual, other things start to get in the way and Barry has to focus on other things."

Executive producer Andrew Kreisberg also teased that Caitlin has discovered the truth about her ex-fiancee Ronnie Raymond (Robbie Amell), teasing details for an upcoming episode where Ronnie meets up with the other half of Firestorm, Dr. Martin Stein (Victor Garber).

"She discovers the truth of Firestorm and decides she has to let it go because Ronnie is no longer Ronnie anymore. Episode 13 is called "The Nuclear Man", and we have Victor Garber and Robbie Amell in that episode, so you're going to get a lot of the answers of what happened to Ronnie the night of the explosion. Even episodes 10, 11, and 12 have bits of the puzzle to figuring out the secret behind Firestorm, and then General Eiling, played by Clancy Brown, shows up because Firestorm is his new target."