'Therefore I Am' delves into the backstory of The Thinker and The Mechanic, connecting their story to season 1 and presenting them as a tough duo to defeat.

WARNING - This review contains SPOILERS for The Flash season 4, episode 7

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All season long, The Flash has been hearkening back to its earlier days - season 1, especially, reflecting its more upbeat tone and lighter atmosphere. But there were serious and at times dark moments in season 1, beginning with Harrison Wells (actually Eobard Thawne in disguise) activating the particle accelerator and putting that first season's events in motion. And in its most obvious callback to season 1 yet, 'Therefore I Am' manages to tie its own season arc in with that time frame, revealing The Thinker's origin and connecting it the same fateful night on which Barry was also transformed.

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In tandem, this episode is exploring two time periods: the first is that matter of fact explanation for how Clifford Devoe becomes the man in the floating chair, The Thinker. It's a clear cut explanation of a man who wished to exceed the limitations of his own brain, to expand his mind in a way that would make him smarter than anyone who's ever lived. A lofty goal, to be sure, but one he is more than able to accomplish with the right help - namely, his wife, Marlize and soon to be partner-in-crime, The Mechanic. As it's later explained, he comes up with the ideas and she executes them, and as a pair they work together flawlessly. With her creation of the thinking cap, he is able to supercharge his brain during the particle accelerator's explosion, and as his advanced mind begins draining the life from his body, she works tirelessly to create the tech necessary to keep him alive, eventually leading to that floating chair and all its various accoutrements. In a bizarre fashion, their teamwork is like the evil inversion of Barry and Iris' partnership - except they're actually much better at it, deeply supportive and loving of one another and laser-focused on their evil agenda. The specifics of their goals are still hidden, but this one episode gives ample reason to believe they're going to be able to pull it off, whatever it is.

The Flash Season 4 Therefore I Am Clifford and Marlize Devoe sit side by side

It's during these flashbacks to four years ago that The Flash has some fun, making sure to include a scene in which the Devoes confront Wells (again, actually Thawne) and share a bit of banter about what it is turning on the particle accelerator will achieve. The episode has Wells dropping the obvious hints that he knows the full story of the married couple and what will soon happen to them, playing with the fact he's a time traveler who knows Barry Allen's story better than anyone. But in addition to being a neat and very direct reference to season 1, it also further reinforces the idea that The Thinker is an adversary that will leave a lasting impact on Barry and those he loves. Again, we haven't yet been enlightened to the full scope of what the Devoes are up to, but seeing as other villains of The Flash seem to keep bringing them up, it must leave an impression.

The other plot is where 'Therefore I Am' begins to go a little off the rails, falling back on old habits and tired tropes to create tension between the Devoes and Barry (and basically just fill the air between scenes of The Thinker's backstory). What the episode delivers as its A-plot is Barry growing wildly suspicious of Clifford and Marlize, basing it all on mere coincidences and his own gut feeling rather than any solid evidence. That we're also supposed to know Barry is correct in his assumptions makes it all the more irritating, as if we're meant to be rooting for Barry as he acts like a complete twit. It's a weird choice for the series to make, seemingly having Barry regress for no other reason than to create conflict among him and the rest of the team. If anything, the best that comes of this story line are more scenes in which the Devoes can show off how easily they're playing Barry, as they take action against him and force him to face some consequences for his terrible behavior. Ultimately, it's unclear what this plot was meant to accomplish or communicate about its characters because all it really does is paint Barry in a very bad light.

The Flash Season 4 Therefore I Am Barry Allen Joe West

And of course, none of this seems to matter in the long run (and it's highly doubtful Barry's suspension from the police force is something that sticks) because once he gets Devoe to confess that he is the bad guy Barry suspects he is, Barry tells Team Flash and they all believe him, conflict resolved. Their focus now switches to the upcoming nuptials for Barry and Iris, and it's unlikely that The Thinker and The Mechanic will even be involved at all seeing as the big crossover event, 'Crisis on Earth-X' is set to introduce evil, fascist doppelgangers of characters like Green Arrow and Supergirl. Knowing this departure from season 4's main story line is what comes next makes it even more baffling that this episodes goes to all the trouble of making Barry look like a paranoid lunatic, only to backtrack on all of it in the span of its runtime.

At least we now know exactly who The Thinker and The Mechanic are as 'Therefore I Am' does an wonderful job of developing them as intriguing, almost sympathetic villains. Their partnership is a strange inversion of what Barry and Iris almost have, setting them up to be unusual adversaries that are sure to be twice as hard to defeat.

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The Flash season 4 continues next Tuesday with Part 3 of the crossover event, 'Crisis on Earth-X' at 8pm/9c on The CW.