"Don't Run" is the ninth episode and midseason finale of the fourth season of The Flash, and the seventy-eighth episode overall. It aired on December 5, 2017.


Amunet kidnaps Caitlin and puts meta-dampener handcuffs on her to keep her from turning into Killer Frost. Amunet tells Caitlin she needs her to perform a tricky medical task and if Caitlin fails, Amunet will kill her. Meanwhile, The Thinker traps The Flash in a speedster-proof prison. With the clock ticking, The Team doesn’t have the time or resources to track both Caitlin and Barry so Iris is forced to choose who to save.[1]




  • The title is a reference to Barry's final line as the CCPD show up to arrest him right after he realizes that Clifford DeVoe, now possessing Dominic Lanse's body, planted knives along with his old body to make it look as if Barry had killed him.
    • This is the second episode to feature Barry getting arrested; this time for a crime he didn't commit.
  • Cisco likens Harry to Ebenezer Scrooge and the Grinch. In reply, Harry claims that "you're a mean one, I wouldn't touch you with a 39 and a half foot pole", quoting the song "You're a Mean One, Mr. Grinch" from the 1966 TV special Dr. Seuss' How the Grinch Stole Christmas!.
  • Cisco calls both Harry and Ralph humbugs, referencing Ebenezer Scrooge's catchphrase in the Charles Dickens novella A Christmas Carol.
    • Cisco claims this as a "Festivus miracle", a phrase commonly used by Kramer in the TV series Seinfeld.
  • When Amunet prevents Caitlin from transforming into Killer Frost, she quips that "Frosty melted away", referencing the 1969 TV special Frosty the Snowman in which the protagonist melts.
  • Cisco calls Amunet an "evil Mary Poppins", referencing her English accent.
  • When DeVoe (disguised as Dominic) goes to describe the West house, Cisco suggests "bitchin'", a callback to the season premiere, "The Flash Reborn", in which a decoded message from a discombobulated Barry reads "This house is bitchin'".
  • This episode is the beginning of the famous and critically acclaimed The Flash comic story, The Trial of The Flash which begins in issue #323 and ends in #350. It follows Barry's trial for supposedly killing an individual.
    • This storyline was foreshadowed in the episode, "Fast Enough", when Barry ran through the Speed Force a witnessed a vision of himself in prison.
  • DeVoe gains the ability of telepathy through his transferring his mind and consciousness into the body of Dominic. In the DC comics, DeVoe had the ability of telepathy, however, Barry Allen is immune to telepathy.


  1. Flash Spoilers: “Don’t Run” Description - FalshTVNews