Flash Back

"Flash Back" is the upcoming seventeenth episode of the second season of The Flash, and the fortieth episode overall. It will air on March 29, 2016.

Cast

 * Grant Gustin as Barry Allen/The Flash
 * Danielle Panabaker as Caitlin Snow
 * Carlos Valdes as Cisco Ramon
 * Tom Cavanagh as Eobard Thawne/Harrison Wells

Synopsis
After the shocking revelation that Zoom is Jay Garrick, Barry is more determined than ever to get back to Earth-2 to stop Zoom forever. Desperate to find a way to increase his speed, Barry decides to travel back in time and masquerade as his earlier self in order to get his arch-nemesis, Dr. Harrison Wells/Eobard Thawne, to teach him how to run faster. However, things don't go as planned and Barry is stunned to face familiar foe Hartley Rathaway, as well as old friend Eddie Thawne. Iris makes peace with her past in order to embrace her future.

Trivia

 * Hartley was last seen in Crazy for You.