"Do you know what makes a great speedster? It isn't their speed. It's being the light that everyone needs when the world grows dark. It's the kind of person they are. The kind of person that always wants to help. That's why being the Flash is your destiny. It's your way of helping others. But it isn't mine."
Iris West-Allen to Barry Allen on her dreams
"Run, Iris, Run" is the sixteenth episode of the fourth season of The Flash, and the eighty-fifth episode overall. It aired on March 13, 2018.


Team Flash confronts a new bus meta, Matthew AKA Melting Point, with the ability to swap people's DNA. During a battle with Team Flash, Matthew transfers Barry's super speed to Iris. Now, with a new threat unleashed on Central City, Barry must act as the team leader while Iris takes on the mantle of superhero speedster in order to defeat their new foe.[src]


Promotional images



  • The episode's title plays off the recurring phrase, "Run, Barry, run", which has been used to encourage Barry Allen to run faster throughout the series. The alternative phrase featuring Iris' name is used by Barry when Iris has to create a tidal wave to put out Jaco Birch's thermal cyclone.
  • Cisco is appalled when Harry suggests "Frankensteining" all of the remaining bus metas' DNAs together, referencing the Mary Shelley novel Frankenstein in which a scientist puts together body parts to create a makeshift creature.
  • Cisco comments that the heat generated to melt the bank vault - 6,000 °F - is 10 times the power of Mick Rory's Heat gun.
  • After Ralph is anxious that he'll get "terminated" by DeVoe, he claims that he's Sarah Connor, a protagonist of the Terminator franchise.
  • Cisco mentions that DeVoe's machinations are warping his brain, likening the situation to the 2004 film Spider-Man 2.
  • Discussing Harry wearing the Thinking Cap, Cisco vows to pull him out before he "[starts] acting like Locutus of Borg and [starts] assimilating everybody", referencing a character from the Star Trek franchise.
  • When Harry and Cisco are talking about how to defeat DeVoe, Harry suggests "We alter each bus meta's DNA by performing intercellular surgery." Cisco responds, "And what? Turn them into chickens?" A similar situation happened on the show Red Dwarf, where an old spacecraft had turned Dave Lister into a chicken.
  • This is the eighth episode in the Arrowverse and the second episode of The Flash to be named after a character in a civilian sense, after "Sara", "The Secret Origin of Felicity Smoak", "Who is Harrison Wells?", "My Name Is Oliver Queen", "Alex", "Zari", and "When Harry Met Harry...".
  • Jaco Birch may be named after J.J. Birch, a pseudonym of DC comic book artist Joe Brozowski who worked for a long time on comics about a fire-related character, Firestorm.
  • Iris' blog post "The Fire within Central City...and Us All" is dated March 13, 2018, the day that this episode aired.


  • When Cisco and Joe West are examining the vault door after Eric Frye melted through it, Cisco says the door was 10 inches thick and required 6,000 °F to burn through it. Yet none of the money, which was laying out in the open no more than a few feet from the vault door, shows any sign of having been exposed to such high heat. The money should have been burned up, or at the very least, greatly singed.


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