Barry continues to train Jesse and when a new meta human, Mirror Master, appears on the scene he lets her tag along. Mirror Master has teamed up with his old partner, Top, and is looking for Snart to even a score. Jesse is quick to join the chase but defies one of Barry’s orders which results in disastrous consequences.

Barry travels to the future to find out Savitar’s still unknown identity in the hopes of saving Iris. Upon his arrival in 2024, Barry encounters future versions of his Team Flash friends, who, following the death of Iris, have become very different people, profoundly impacted by their showdown with Savitar. It will be up to Barry to infuse a sense of hope back into the team, as he proves to be hero his future friends have been waiting for. Meanwhile, back in 2017, the hunt for Killer Frost continues.

When an experiment to save Barry's speed backfires, Nash Wells searches for a way to save The Flash and comes up with a dangerous plan. Meanwhile, Iris makes a startling realization inside the Mirrorverse and Cecile faces off with Rosa Dillon.

Barry meets Black Lightning at the Hall of Justice after things take a dire turn with Despero. Iris suspects something is off with Despero's vision of the future so she seeks help from a powerful ally.

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

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.