"Cause and XS" is the fourteenth episode of the fifth season of The Flash, and the one-hundred-sixth episode overall. It aired on February 12, 2019.


After Iris lands in serious danger, Nora races to save her mother. Barry puts the finishing touches on the meta-human cure, leaving Cisco with a rare night off so he decides to take Kamilla on a date.[1]


  • The episode's title is a play on the phrase "cause and effect".
    • Which coincidentally was an episode back in Season 3 of The Flash
  • This episode is the shortest clocking in at under 35 minutes.
  • Nora resets the timeline 52 times, a reference to the famous DC number 52.
  • When Barry teaches Nora about time travel, he gives her the same explanation Jay Garrick gave him in "Paradox".
  • The animation when Nora runs back in time is somewhat similar to the animation of Earth-90's Barry Allen being thrown through time in The Flash​.
  • The events of this episode are very similar to the events of the DC's Legends of Tomorrow​ episode "Here I Go Again", where Zari dreams that she's stuck in a time loop, reliving the same hour over and over again with the Waverider exploding at the end of each loop.


  1. "The Flash - Episode 5.14 - Cause and XS - Press Release" - SpoilerTV

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