"The Flash" spoiler alert: There will be a villain returning on "The Flash" episode 7!

According to TV Line report, Robert Knepper will reprise the role as William Tockman (aka The Clock King) in Episode 7. This comic character, The Clock King is the first villain to show up in both Starling and Central City having faced off against Oliver and company in "Arrow."

As per Executive Producer Andrew Kreisberg, "We wanted to give Barry a real challenge... TWO bad guys! Fighting both a new enemy and one of our scariest and most successful Arrow villains in The Clock King."

The producer didn't give any word yet on who that other villain might be. This villain will be the reason for having a crossover between "Arrow" and "The Flash."

Meanwhile, since Reverse Flash appeared in episode 6, many fans are craving to figure out who is this guy. As a matter of fact, some said that Harrison Wells (Tom Cavanagh) could be the Reverse Flash. While on Bustle report, some fans' theories are pointing that Harrison Wells is Professor Zoom or that he's actually Barry Allen from the future.

The previous episodes of this TV series showed that Wells is actually pretending that he can't walk. And as of the moment, the series hasn't given any hint why this guy pretends he can't walk.

Executive producer Geoff Johns told The Hollywood Reporter, "Harrison Wells is a new character that was created. The name obviously is brand-new. I don't think we can say anything else about it."

Grant Gustin who played Barry Allen a.k.a The Flash, told EW, "Barry will actually get to come face to face with him, not just running with him, but standing face to face with him, looking at him. He's vibrating, so he doesn't know who he is. We don't see his face. No characters see his face and the audience doesn't necessarily see his face either, but Barry gets to hear him say that he killed his mom."

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