The Flash Season 4 finale promo The CW has released The Flash Season 4 finale promo, which you can watch in the player below. Titled “We Are The Flash,” the episode will air on May 22 and is described as follows: “Team Flash gets help from a surprising ally in their battle against DeVoe (Neil Sandilands).” David McWhirter directed the episode, which was written by Todd Helbing & Eric Wallace. RELATED: The CW Renews 10 Series, Including All Superhero Shows The Flash stars Grant Gustin as Barry Allen/The Flash, Candice Patton as Iris West, Danielle Panabaker as Caitlin Snow, Carlos Valdes as Cisco Ramo, Tom Cavanagh as Dr.