Barry feels guilty for what happened to Caitlin, and Mark comes up with a plan that makes everyone skeptical. Meanwhile, Red Death looms in Central City and commands that failure is not an option. Joe asks Cecile to make a choice that leads Cecile to think about the greater good. Allegra and Chester take a step in a new direction. Lastly, old friends pay an unexpected visit to S.T.A.R. Labs.

Barry creates a map book to guide him and Iris throughout their future in order to keep her safe, but the results are not what he expected, and instead, they relive the same day over and over again. Joe has a heart-to-heart with Cecile. A new big bad is introduced to Team Flash and friends and foes, old and new, begin to descend upon Central City.

With The Flash still reeling from everything that just happened, the rest of the team rallies to support him when he needs it the most.

The Flash and team are in for the fight of their lives, meanwhile, Iris discovers the cause of her time sickness.

With a new speedster in town, The Flash gets much more than he bargained for, meanwhile Cecile’s powers experience a growth spurt allowing her to aid Team Flash on an entirely different level.

The Flash goes off the grid to look for answers about a new Meta in town. Meanwhile, Allegra pulls out all of the stops at CC Citizen Media, to protect a source and a friend.

The Flash gets blasted with a shockwave forcing his body to age prematurely.