- Grant Gustin (Barry Allen / The Flash)
- Candice Patton (Iris West-Allen)
- Danielle Panabaker (Khione)
- Danielle Nicolet (Cecile Horton)
- Kayla Compton (Allegra Garcia)
- Brandon McKnight (Chester P. Runk)
- Jon Cor (Mark Blaine / Chillblaine)
The Flash — S3E20
Episode: I Know Who You Are
Air Date: 2017-05-02
Runtime: 42 min
Overview
Barry and the team meet Tracy Brand, a scientist, who may be the key to stopping Savitar. Unfortunately, Killer Frost is also after Tracy so Team Flash must battle their old friend, which proves to be particularly difficult for Cisco. Joe and Cecile’s relationship takes a big turn.