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The Flash S04E20, Therefore She IsS04E20

The Flash · Season 4

The Flash season 4 episode 20: Therefore She Is

Aired 1 May 201842 minRated TV-PG

6.9TMDB · 31 votesMark watched

Where to watch The Flash Season 4 in Australia

The Flash season 4 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 $29.99, Fetch TV from $29.99 and Prime Video Store from $24.99.

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Stream (subscription)

Free

Buy or rent

Availability checked 16 November 2026.

What happens in “Therefore She Is”

Barry and Team Flash team up with Gypsy to try to thwart Thinker's plan. Meanwhile, Cisco and Gypsy have a heart to heart talk about their relationship.

Episode summary: TMDB.

Before you watch

  • It is episode 20 of 23 of season 4, so watch episodes 1 to 19 first.
  • It runs about 42 minutes.
  • Directed by Rob J. Greenlea, written by Sterling Gates and Thomas Pound.
  • TMDB users rate it 6.9 out of 10 (31 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
Rob J. Greenlea
Writers
Sterling GatesThomas Pound
Guest stars
Danielle Nicolet as Cecile HortonZachary Gulka as Security GuardKim Suzanne Engelbrecht as Marlize DeVoe / The MechanicLaura Jaye as ModeratorPanta Mosleh as Peace Corps VolunteerJessica Camacho as GypsySean Poague as Accelerated ManNeil Sandilands as Clifford DeVoe / The Thinker

Credits: TMDB.

More from The Flash Season 4

Previous · S04E19Fury Rogue24 April 2018Next · S04E21Harry and the Harrisons8 May 2018
  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
  23. E23

Every episode of Season 4The 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.