One of Barry Allen's defining characteristics on The Flash has always been his hopefulness, of never giving up on trying to battle evil and save his friends, family, and the world. That fortitude has been tested greatly over the last three seasons, and been especially difficult to sustain when it comes to Iris West's seemingly inescapable fate.

In the last episode, 'Once and Future Flash', Barry was once again thwarted in his attempts to uncover Savitar's true identity and find a way to defeat him. Traveling ahead in time to 2024, the speedster discovered a bleak future, with Team Flash broken in devastating ways. Future Barry revealed he had finally trapped Savitar with technology that was invented four years too late, and an imprisoned Killer Frost refused to share her knowledge of who the "God of Speed" really is.

While viewers did get to see the moment that Savitar unmasked himself to our current timeline's Caitlin, we were deprived of seeing his face for ourselves. The trailer for next week's episode 'I Know Who You Are', which you can watch above, implies we may finally get the reveal we've been waiting for. The clips include scenes with Barry, Cisco, and Killer Frost, all focusing on Savitar's intimate knowledge of Team Flash's previous, current, and future actions.

The clues that Savitar has been dropping all along on season 3 of The Flash about his foreknowledge of their actions, added to the instant recognition and trust from Killer Frost, seem to point to the evil speedster being a future version of someone on Team Flash -- possibly even Barry himself. Wally's catatonic state in 2024, which seems to be as much about emotional shock as physical injury, adds further proof that the final reveal will be as surprising and painful as the cast and showrunners have promised.

The official synopsis for The Flash episode 'I Know Who You Are' also indicates that Cisco will be battling Killer Frost, and we can see a cool shot of their colliding powers in the above clip. The trailer ends with Barry uttering the title line, "I know who you are," and fans will be hoping that isn't a cliffhanger tease that leaves us hanging once again for another episode.

The Flash airs Tuesdays at 8pm on The CW.

Next: The Flash: The Once And Future Flash Review & Discussion

Source: The CW