The Flash (2014– )
27 user 12 critic

Cause and XS 

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


Rachel Talalay


Greg Berlanti (developed by), Andrew Kreisberg (developed by) | 8 more credits »

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Episode complete credited cast:
Grant Gustin ... Barry Allen / The Flash
Candice Patton ... Iris West-Allen
Danielle Panabaker ... Caitlin Snow / Killer Frost
Carlos Valdes ... Cisco Ramon / Vibe
Hartley Sawyer ... Ralph Dibny / Elongated Man
Danielle Nicolet ... Cecille Horton
Jessica Parker Kennedy ... Nora West-Allen / XS
Chris Klein ... Orlin Dwyer / Cicada
Tom Cavanagh ... Sherloque Wells / Eobard Thawne
Jesse L. Martin ... Joe West (credit only)
Victoria Park ... Kamilla Hwang
Lucy Harvey Lucy Harvey ... Carolyn the Barista
Megan Helbing ... Megan the Barista
Jerry Yang ... Ian the Patron
Thomas Miller ... Stephan the Patron


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

Plot Summary | Add Synopsis


TV-PG | See all certifications »

Parents Guide:

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Release Date:

12 February 2019 (USA) See more »

Filming Locations:

British Columbia, Canada

Company Credits

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Technical Specs


Sound Mix:




Aspect Ratio:

16:9 HD
See full technical specs »

Did You Know?


Nora has altered the timeline more than any speedster, changing the timeline at least 54 times, not counting the uses of her time reversal power. See more »


The show has long since established its "rules" for time travel, and thus far, one of the most pivotal ones has always been that the person going back in time would also exist in the past to which they're travelling. This vital rule is completely shattered here, without so much as an attempt of an explanation for the deviation (not to mention how this "cheat" pretty much nullifies the whole premise of the plot). See more »


Barry Allen: We have to wait how long before we can use the meta-human cure?
Cisco Ramon: Not even that long.
Iris West-Allen: Cisco.
Cisco Ramon: [snapping his fingers] It's gonna go by like that.
Iris West-Allen: Cisco.
Cisco Ramon: 29 days.
Nora West-Allen: A month?
Cisco Ramon: I know, right? Just one, teeny, tiny month until we stop Cicada's purge. You know, historically speaking, this is way faster than we've ever stopped a big bad, so...
See more »


References Breakin' (1984) See more »

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User Reviews

Too much XS!
14 February 2019 | by asb_deutschSee all my reviews

PROS: Nice to see the evil side of Cicada instead of being Papa John. This episode focuses more on Emotional Intelligence and the ending reminds me of Season 3. I don't want to go in for more details otherwise it will spoil the fun! CONS: Nora needs to grow up now! Because of her, the script-writers are slowing up things. No need to make this episode a Valentine's Day episode. Time to concentrate more on Cicada and press the pedal! VERDICT: My ratings (based on what I marked on IMDb): Season 1: 200/23 = 8.69; Season 2: 193/23= 8.23; Season 3: 188/23= 8.17; Season 4: 146/23= 6.65 and Season 5= 99/14 = 7.07 (This episode = 6.5/10)

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