Flash: What's Past Is Prologue

"What's Past Is Prologue" is the eighth episode of season five of the superhero action series The Flash and the one-hundredth episode of the series overall. It was directed by Tom Cavanagh with a teleplay written by Todd Helbing and Lauren Certo. It first aired on the CW Network on Tuesday, December 4th, 2018 at 8:00 pm.

Appearances

 * Flash, Barry Allen
 * Elongated Man, Ralph Dibny
 * Iris West-Allen
 * Killer Frost, Caitlin Snow
 * Vibe, Cisco Ramon
 * XS, Nora West-Allen


 * The Flash, Barry Allen (Earth-90)
 * Doctor Ambres
 * Grace Gibbons
 * Harry Wells
 * Sherloque Wells


 * Cicada, Orlin Dwyer
 * Harrison Wells/Eobard Thawne
 * The Monitor, Mar Novu
 * Savitar, Barry Allen
 * Zoom, Hunter Zolomon


 * Clyde Mardon
 * Dawn Allen
 * Grodd
 * Hartley Rathaway
 * Henry Allen
 * Jesse Wells
 * Joe West
 * King Shark
 * Libby Lawrence
 * Mark Mardon
 * Marlize DeVoe
 * Martin Stein
 * Nora Allen
 * Ronnie Raymond
 * Stargirl (Earth-90)
 * Thinker, Clifford DeVoe


 * Legion of Super-Heroes
 * Team Flash


 * Humans
 * Altered humans
 * Apes
 * Gorillas


 * Time wraiths


 * Earth-1
 * Central City
 * Central City Medical Center
 * Flash Museum
 * Iron Heights (2049)
 * S.T.A.R. Labs


 * Earth-90


 * Book of Destiny
 * Cicada's dagger
 * Computer
 * Dark matter
 * Flash's costume ring
 * Gideon
 * Particle accelerator
 * Thinking cap


 * Ambulance
 * S.T.A.R. Labs Mobile Resource Unit
 * Van


 * Elasticity
 * Electromagnetism
 * Cryokinesis
 * Phasing
 * Super-speed


 * 2013
 * 2016
 * 2018
 * 2049
 * Artificial intelligence
 * Chronal anomalies
 * Hospital
 * Paramedic
 * Prison
 * Time travel

Notes & Trivia

 * The Flash was developed for television by Greg Berlanti, Andrew Kreisberg, and Geoff Johns.


 * This episode is rated TV-PG.


 * This episode is production code number T27.13758.


 * This is Lauren Certo's tenth episode of The Flash as a writer. She previously wrote "News Flash".


 * This episode retroactively establishes that the reality from the 1990 Flash TV series is Earth-90.


 * This episode first aired on actor Tony Todd's birthday. Todd was born in 1954 and provides the voice for Zoom in this episode.


 * Actors Tony Todd, Benita Ha, and Troy Rudolph have all appeared on episodes of Smallville, which is another DC Comics licensed property.