For the titular book, see The Runaway Dinosaur (Earth-1).

"I don't understand. If I'm the Flash then why are you doing this to me? Why do I have to catch this "thing" before you let me go back?"
Barry Allen upon questioning The Speed Force (as Iris West) about the purpose of his speed.
"The Runaway Dinosaur" is the twenty-first episode of the second season of The Flash, and the forty-fourth episode overall. It aired on May 10, 2016.


With Barry gone, the team must figure out a way to handle the return of an old enemy – Girder. Realizing Girder is retracing his steps from his last attack, Iris volunteers to act as bait to trap him in S.T.A.R. Labs. Meanwhile, Barry fights to return to his old life.[2]


Promotional images



  • The episode's title comes from the name of Barry's favorite childhood storybook.
  • Cisco gives several zombie references in the episode
    • The Walking Dead, referencing the long run show about the zombie apocalypse.
    • Calling Girder iZombie is a reference to another CW TV show that's based on the Vertigo comic series. Greg Finley had a recurring role on the show.
  • When Barry shared his Speed Force momentarily to revive Jesse, this was an ability that in the comics was exclusive to Wally West as a speedster.
  • Jason Mewes famously appeared with Kevin Smith as the comedic duo Jay and Silent Bob in Smith's View Askewniverse projects including Clerks and their own film Jay and Silent Bob Strike Back.
  • Kevin Smith stated on Instagram that the final scene between Caitlin and Zoom was filmed during production of the previous episode to allow Danielle Panabaker and Teddy Sears the following week off.


  1. Jay Mewes Plays A Metahuman On Kevin Smith's The Flash Episode -
  2. Barry starts seeing things which are actually just the speed force controlling mindThe Flash: Official Description for Kevin Smith’s Episode “The Runaway Dinosaur” - FlashTVNews
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