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The Flash S05E21, The Girl With The Red LightningS05E21

The Flash · Season 5

The Flash season 5 episode 21: The Girl With The Red Lightning

Aired 7 May 201942 minRated TV-PG

6.8TMDB · 21 votesMark watched

Where to watch The Flash Season 5 in Australia

The Flash season 5 is streaming in Australia on Prime Video (subscription), HBO Max (subscription) and Stan (subscription), and free on 9Now. You can also buy it on Apple TV from $7.99, Fetch TV from $44.99 and Prime Video Store from $29.99.

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Free

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Availability checked 16 November 2026.

What happens in “The Girl With The Red Lightning”

Team Flash is on high alert after Cicada II threatens to unleash a dangerous virus that would put all meta-humans at risk.

Episode summary: TMDB.

Before you watch

  • It is episode 21 of 22 of season 5, so watch episodes 1 to 20 first.
  • It runs about 42 minutes.
  • Directed by Stefan Pleszczynski, written by Thomas Pound and Judalina Neira.
  • TMDB users rate it 6.8 out of 10 (21 votes).

The Flash trailer

The official trailer for the series (no preview of this episode has been published).

The Flash trailerPlay video: The Flash trailer

Cast and crew of this episode

Director
Stefan Pleszczynski
Writers
Thomas PoundJudalina Neira
Guest stars
Kimberly Williams-Paisley as Renee AdlerSarah Carter as Grace Gibbons / Cicada IIEverick Golding as Trevor ShinickBrandon Bagg as OfficerSonia Beeksma as News ReporterAliya Boulanger as Female UniJanet Glassford as Surly MetaKareem Malcolm as Male Uni

Credits: TMDB.

More from The Flash Season 5

Previous · S05E20Gone Rogue30 April 2019
S05E22Next · S05E22Legacy14 May 2019
  1. E01
  2. E02
  3. E03
  4. E04
  5. E05
  6. E06
  7. E07
  8. E08
  9. E09
  10. E10
  11. E11
  12. E12
  13. E13
  14. E14
  15. E15
  16. E16
  17. E17
  18. E18
  19. E19
  20. E20
  21. E21
  22. E22

Every episode of Season 5The Flash episode guide

Episode names, air dates, runtimes, stills and ratings: TMDB. Air dates are the first broadcast anywhere; where it streams is our daily Australian check.