Iris becomes a speedster in the next episode of “The Flash.”

According to the synopsis for Season 4, episode 16 of the CW series, bus meta Matthew (Leonardo Nam), aka Melting Pot, who has the ability to swap people’s DNA, accidentally takes Barry’s (Grant Gustin) Speed Force powers and gives it to Iris.

In the trailer for the hour, Barry manages to save Iris from Matthew who seemingly took her as hostage. When Matthew escapes, Barry tries to chase him but is taken aback when he notices that his super speed  has suddenly gone.

“I lost my speed,” a surprised Barry tells Iris and Joe (Jesse L. Martin).

Soon after, Iris finds her hand vibrating, and says, “Uh, guys, I think I found it.”

With a new threat unleashed on Central City, Barry is left with no choice but to serve as the team leader while Iris takes on the mantle of The Flash in order to defeat their new foe.

Promo photos for the installment show that the team’s new enemy is none other than Jaco Birch (Max Adler).  According to FlashTVNews, Jaco is described as “an obsessive music fanatic who worships at the altar of classic heavy metal.” He’s also a roadie for unknown contemporary metal bands and loves to set things on fire.

Adler’s upcoming appearance on the series was first revealed when he was spotted filming scenes with Patton at Harbour Green Park in downtown Vancouver last month.

While Iris looks like she’s having fun being a speedster, Hartley Sawyer revealed to Variety last month that his character Ralph has some problems with Iris getting Speed Force powers.

“I think the only thing I can tease is that he struggles with it,” Sawyer said of Ralph when asked how the Elongated Man reacts to Iris becoming a speedster. “It does give Ralph and Iris to have some real one-on-one time which is really interesting. It’s a cool dynamic and a cool relationship that they have.”

“The Flash” Season 4, episode 16, aptly titled “Run, Iris, Run,” airs on Tuesday, March 13 at 8 p.m. EDT on The CW.