Grunberg’s character will debut in the November 22 episode, an installment titled “Killer Frost.” That episode was also directed by Kevin Smith — who is also Grunberg’s co-host on AMC’s talk show “Geeking Out.” You can read a synopsis of the ep, which features Caitlin Snow’s (Danielle Panabaker) full turn to Killer Frost, below.
KEVIN SMITH DIRECTS; KILLER FROST EMERGES — Caitlin (Danielle Panabaker) uses her powers to save Barry (Grant Gustin) but as her mother predicted, the effort unleashes her inner Killer Frost. Killer Frost goes on a rampage looking for Dr. Alchemy, kidnapping Julian (Tom Felton) and battling both The Flash and Vibe (Carlos Valdes). Meanwhile, Joe (Jesse L. Martin) and H.R. (Tom Cavanagh) have a heart to heart talk. Kevin Smith directed the episode with story by Judalina Neira and teleplay by Andrew Kreisberg & Brooke Roberts (#307).