Brief spoilers below for The Flash's latest episode, "Girls Night Out."
The Flash has had a ton of interesting villains causing havoc in Central City, but the Season 4 big bad The Thinker may be it's most curiously intriguing one yet, largely because we know so little about him. Barry is slightly more than just curious about he who is known as DeVoe, and as Season 4 goes on, it looks like Barry will start to get obsessed with discovering who The Thinker is, and that mystery will lead to some dark turns. According to star Grant Gustin:
Barry's taking it pretty seriously right away. He starts to, before anybody else on the team, know for sure that this is our guy and starts to become a little bit obsessed with getting him, because he doesn't want things to get out of hand again, as they always do. . . . Barry's starting to get obsessed that this is our guy, he realizes that it's going to get dirty quick, and before it gets dirty he wants to get ahead of this guy. And then they start to realize what a challenging foe he's going to be and different than any other speedsters we've faced in the past. He's not a speedster, he's something we've never seen before. Things are going to take a dark turn quickly in the middle of the year.
I kinda like thinking about Barry Allen in a neo-noir, pulling a fedora brim over his eyes as he steps into a dive bar in search of information about DeVoe. (After "Girls Night Out," he can probably hold his super-liquor a little better.) But Barry is not the kind of character who discovers facts through quiet conversations in dimly lit rooms. It's likely going to take one of Cisco's wicked complicated gadgets in order to put some of these pieces together as far as Thinker's identity and motives are concerned, and it'll seemingly come at a time when Team Flash is going through one of its darker patches.
It's not exactly clear how dark The Flash will get as The Thinker's mystery continues, but we're betting DeVoe's big plan to destroy The Flash is not one inspired by birthday cakes and petting zoos. He's bound to be connected to some awful memory that Barry has, likely involving a dead relative. Or perhaps Barry is to blame for some horrible incident that happened in DeVoe's life that turned him into a scarred and blue-tinged baddie with a floating chair that has hologram chess installed in it.
Barry's obsession will probably cause some strife between him and Iris and the rest of Team Flash, especially if no one believes him at first about it being DeVoe. But so long as Iris doesn't get taken captive yet again, we're willing to deal with some more counseling-worthy problems coming up. And according to ComicBook.com, Grant Gustin seems pretty optimistic that the dark turns won't actually destroy Team Flash in any big ways.
He's still Barry and he's hot-headed and when he's sure he's right, he's stubborn. But the team is in a good place this year so we're not going to see any massive hiccups with the team at this point in the season. They'll recover.