For its first three seasons, The CW's superhero series The Flash featured an overarching villain with the same power set as Barry Allen. It began with Eobard Thawne's Reverse-Flash in Season 1; then it continued with Jay Garrick Hunter Zolomon's Zoom in Season 2; and finally, in Season 3, the speedster villain Savitar revealed himself as a duplicate Barry Allen from the future. Finally, the series changed things up in Season 4 with the introduction of the Thinker -- and that trend will keep going in Season 5.

Earlier this summer, during Comic-Con International in San Diego, it was revealed that the super-villain known as Cicada would be the next big villain of the show. Now, with the Season 5 premiere of The Flash a little more than a month away, The CW has released an official promo for the return of the series, which features a few big teases about what to expect in this year's storylines.

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The trailer once again devotes a great bit of time to Barry and Iris' time-traveling daughter Nora West-Allen, whom we know will be a driving force behind Season 5. New cast member Jessica Parker Kennedy has joined The Flash as a series regular, making it clear that she will have an important role to play on the series.

At the close of Season 4, Nora not only revealed herself to her parents, but she also ominously informed them that she had made a big mistake. While it wasn't clear at the time what she was referring to, this Season 5 promo gives us a clue: whatever Nora did, she changed the timeline, and it's beginning to have ripple effects. According to her, Cicada is a villain that Team Flash should have defeated -- but now, with the timeline changed, all bets are off.

The mysterious villain -- who breathes with some sort of mask apparatus and who wields a lighting-bolt shaped knife that cackles with red energy -- is said to be a serial killer. We don't yet know what his plans are on the series, but it appears as if he has an ax (or a lighting bolt) to grind with The Flash and his allies. We can see him stalk his prey in the shadows, and this certainly can't bode well for Barry, Cisco, and the rest of the team.

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Returning Tuesday, October 9, at 8 p.m. ET/PT on The CW, The Flash stars Grant Gustin, Candice Patton, Carlos Valdes, Danielle Panabaker, Tom Cavanaugh, Jesse L. Martin, Danielle Nicolet, Hartley Sawyer, and Jessica Parker Kennedy.