The Flash 1×23 “Fast Enough” (Season Finale) – Wells (Tom Cavanagh) presents Barry (Grant Gustin) with a life-changing choice. Dr. Martin Stein (guest star Victor Garber) and Ronnie Raymond (guest star Robbie Amell) return to help the S.T.A.R. Labs team with this final fight. Dermott Downs directed the episode with story by Greg Berlanti & Andrew Kreisberg and teleplay by Gabrielle Stanton & Andrew Kreisberg (#123). Original airdate 5/19/2015.