Barry enters The Thinker's mind as the Enlightenment begins in the trailer for The Flash season 4 finale, 'We Are The Flash'. The World's Fastest Man (well, one of them) and Team Flash have spent most of season 4 trying to stay one step ahead of Clifford DeVoe aka. The Thinker, but to no avail. Now that the supervillain is on the verge of executing his plan to wipe the minds of every person on earth, Barry is going to try and literally get into his enemy's brain.

The Flash season 4 has taken its time revealing Clifford's end goal piece by piece. More recent episodes have revealed (via flashbacks) how Clifford and his wife, Marlize aka. The Mechanic, met in the first place and how they came to feel the same way about humanity's future and what needs to be done to save the human species from itself. The Thinker and Mechanic started out as pretty two-dimensional baddies bent on the show, so these revelations have served to flesh out their ambitions and set the stage for Marlize's redemption arc in the season finale.

One of the plot threads in this week's The Flash episode, 'Think Fast', followed Iris and Harry as they tracked down Marlize and ultimately asked for her help in stopping Clifford. The CW's synopsis for the season 4 finale indicates that Iris succeed in changing Mrs. DeVoe's mind, teasing that Team Flash "gets help from a surprising ally" as they try and prevent Clifford from carrying out his master stroke (which he calls the Enlightenment). Meanwhile, as the episode trailer reveals, Barry will use The Thinker's floating chair tech to enter his mind and try to stop him.

Then again, it's possible the "surprising ally" is someone else altogether. The Flash season 4 has been hinting at the identity of Jessica Parker Kennedy's mystery character ever since she showed up in the Arrowverse's 'Crisis on Earth-X' crossover last fall. Most recently, it came to light that she's a speedster who has a vested interest in Joe and Cecile's unborn child and could even be their daughter from the future, all grown up. It stands to reason that, whoever Kennedy is playing, her character will show up in the season finale to help Team Flash (what else?) save the world.

Season 4 has had its weak spots (looking at you 'The Trial of The Flash'), but overall it's done a solid job of bringing together its disparate plot threads heading into the finale. The show even took one of its more frustrating new characters, Ralph Dibney aka. Elongated Man, and made his death at The Thinker's hands a poignant one that has resonated throughout the season ever since. And of course, after four years it's refreshing to finally see Barry going toe to toe with someone who isn't a speedster and challenges him in other ways.

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The Flash season 4 concludes Tuesday, May 22 with 'We Are The Flash' on The CW.

Source: The CW