S4·E16 Run, Iris, Run

Episode recap

Team Flash encounters a new metahuman who calls himself Matthew, also known as Melting Pot. The episode opens with the team tracking the individual, whose signature ability is the capacity to exchange DNA between people. During the ensuing confrontation, Melting Pot activates his power on the members of Team Flash, deliberately swapping the genetic template that grants Barry Allen his super‑speed with that of his sister, Iris. The transfer leaves Barry temporarily without his speed while Iris suddenly gains the ability to move at the velocity that has defined Barry’s role as Central City’s fastest hero.

With Barry’s speed removed, the team must adjust quickly. Barry assumes the position of tactical leader, directing the group’s response to the ongoing threat that Melting Pot has released upon the city. Meanwhile, Iris, now endowed with super‑speed, steps into the mantle of a speedster. She learns to harness the newfound velocity, applying it in combat and in the pursuit of the antagonist’s plan. The episode follows the parallel tracks of Barry’s strategic coordination and Iris’s rapid adaptation to her accelerated abilities.

As the battle progresses, the altered dynamics force the team to rely on their non‑speed resources and on Barry’s experience in leading operations without his own powers. Iris’s emergence as a speed‑enabled hero provides a fresh perspective on confronting the meta‑villain’s scheme, and her actions become central to neutralizing the danger that Melting Pot has unleashed on Central City. The climax sees the combined efforts of the team, guided by Barry’s leadership and Iris’s newly acquired speed, culminating in the defeat of the foe.

By the episode’s conclusion, the temporary exchange of powers has reshaped the roles within Team Flash. Barry returns to a position of command without his speed, while Iris gains confidence in her capacity to act as a speedster. The resolution restores the status quo of the team’s composition, setting the stage for future challenges that will again test their adaptability and cooperation.