Flash season 3 episode 20
Grant Gustin as Barry Allen in The Flash season 3 The CW/ Warner Bros TV

The Flash season 3 returns with a new episode this Tuesday, where Savitar's identity will be finally revealed to Barry Allen and Cisco aka Vibe will reluctantly battle Killer Frost. Episode 20 is titled I Know Who You Are, which airs on 2 May, at 8pm EST on The CW Network.

The official synopsis reads as follows:

Barry (Grant Gustin) and the team meet Tracy Brand (guest star Anne Dudek), a scientist, who may be the key to stopping Savitar. Unfortunately, Killer Frost (Danielle Panabaker) is also after Tracy so Team Flash must battle their old friend, which proves to be particularly difficult for Cisco (Carlos Valdes). Joe (Jesse L. Martin) and Cecile's (guest star Danielle Nicolet) relationship takes a big turn.

In the episode, Team Flash will learn that Caitlin aka Killer Forst is now working with Savitar. Grant Gustin, who plays Barry, told TV Line, "Barry is devastated to find out that Killer Frost helped Savitar. And now he's back, and it's happening for real. It looks like she's helping Savitar, so this is another step in the future actually coming true." The first step for Team Flash, therefore, "is making sure there's no team-up here and they get their friend back."

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It is obvious that Caitlin is beyond the pep-talk stage that previously brought her back from the Killer Frost ledge. Carlos Valdes, who plays Cisco, said, "That worked once; I'm not sure it'll work again. We might have to resort to some more desperate measures."

Teasing an intense scene between Cisco and Julian, Valdes told the outlet, "Today I'm doing a scene with the beautiful Tom Felton, who makes it very difficult for me to stay focused on the scene because of how gorgeous he is....They reach a bit of a rift, because Cisco carries these reservations with him as of late about his powers. This is his worst nightmare, because the last thing he wants to do is hurt Caitlin."

The promo for the episode shows Barry confronting Savitar about knowing everything. "Past Present, future you now all of it right? You know our strengths, you know our fears, you know how much we love each other and you know how to use that love against us."

Barry then confidently says, "I know who you are" as Savitar takes off his armour to reveal himself. Click here to watch The Flash season 3 live via The CW app. You can also watch the episode online by clicking here (only in the US).