The Flash (2014)/Cause and Effect

Cause and Effect
Season 3, Episode 21
Airdate	May 9, 2017
Production Number	T27.13121
Written by	Judalina Neira & Lauren Certo
Directed by	David McWhirter
Stream
← 3x20 I Know Who You Are	3x22 → Infantino Street
The Flash — Season Three

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Cause and Effect is the twenty-first episode of the third season of The Flash, and the sixty-seventh episode overall.

Starring: Grant Gustin (Barry Allen / The Flash, Savitar), Candice Patton (Iris West), Danielle Panabaker (Dr. Caitlin Snow / Killer Frost), Carlos Valdes (Cisco Ramon / Vibe), Keiynan Lonsdale (Wally West / Kid Flash)

with Tom Cavanagh (Harrison "H.R." Wells (Earth-19))

and Jesse L. Martin (Detective Joe West)

Special Appearance by Tom Felton (Julian Albert)

Guest Starring: Anne Dudek (Tracy Brand), Danielle Nicolet (Cecile Horton), Richard Zeman (Lucious Coolidge / Heat Monger)

Guest Starring (end credits): Andre Tricoteux (Savitar)

Co-Starring: Liam Hughes (Young Barry), Sasha Rojen (Young Iris), Ken Camroux-Taylor (Judge Hankerson)

Uncredited: Tobin Bell (Savitar (voice))