Run, Iris, Run

"Run, Iris, Run" is the upcoming sixteenth episode of the fourth season of The Flash, and the eighty-fifth overall. It will air on March 13, 2018.

Synopsis
Team Flash confronts a new bus meta, Matthew AKA Melting Pot, with the ability to swap people's DNA. During a battle with Team Flash, Harold 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.

Trivia

 * 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.
 * Iris will suit up in this episode.