'The Flash' Gets Paranoid In "Therefore I Am" Promo

The CW has released a promo for 'Therefore I Am', the upcoming seventh episode of The Flash's fourth season.

The episode shows the ramifications of Barry Allen/The Flash (Grant Gustin) coming face-to-face with Clifford Devoe/The Thinker (Neil Sandilands). As the promo shows, Barry will become consumed by Devoe's seemingly normal identity.

"Barry's taking it pretty seriously right away." Gustin explained during a recent set visit. "He starts to, before anybody else on the team, knows 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."

"We start to see him become … unravel slightly for the first time all season, because he's been pretty put together this year, positive." Gustin continued. "He starts to become a little obsessed with finding this guy and getting everyone to see and be on the same page as him and see that this our guy for sure," he explained. "But everyone else has their doubts for a while."

And as the promo hints, Barry's crusade could have some negative ramifications, particularly on his impending wedding to Iris West (Candice Patton).

"It's troubling for Iris." Patton revealed. "I think she thinks Barry's gotta take a step back or you could end up in a lot of trouble. You can't go after people like that. There's laws and things. There's going to be a little tension there. Iris is gonna be a little worked about how serious he's taking this Devoe character."

The Flash airs Tuesdays at 8/7c on The CW.