The Flash S06E04 There Will Be Blood

The Flash 6x04 "There Will Be Blood" Season 6 Episode 4 Promo trailer - HALLOWEEN EPISODE – Barry’s (Grant Gustin) efforts to prepare Cisco (Carlos Valdes) for Crisis are derailed when Cisco schemes to save Barry’s life instead. Meanwhile, Ramsey Rosso (guest star Sendhil Ramamurthy) uses his deadly new abilities to save his own life, while sacrificing his humanity in the process. Marcus Stokes directed the episode written by Lauren Certo & Sterling Gates (#604). Original airdate 10/29/2019.