Watch: The Flash "The Once and Future Flash" Promo
In order to change the future, Barry must know the future!
Barry has decided not to change the past, but to change the future--with the knowledge of the future!
Check out the promo below for the next episode of The Flash, "The Once and Future Flash," which features a Barry Allen from the future in addition to the return of none other than Killer Frost!
The Flash goes on a break as the episode airs Tuesday, April 25th at 8pm ET.