The Flash
What's Past Is Prologue
TV Flash files “What's Past Is Prologue” as hour 100 of 184 in the TV Flash guide — The Flash (2014–2023) on The CW, season 5, episode 8, aired 2018-12-04, 60 min.
From the desk
How this hour is filed
This leaf is S05E08: listed hour 100 of 184 in the The Flash guide, hour 8 of 22 in season 5. It aired 2018-12-04 (60 min). The listed hour before it is “O Come, All Ye Thankful” (S05E07). Next is “Elseworlds, Part 1” (S05E09).

Catalog log
Broadcast listing — not a TV Flash recap.
To defeat Cicada, Nora comes up with a plan to assemble the necessary components from discarded villain items in the past and hide them in the present. Barry travels back in time to recover the three components, and reluctantly takes Nora with him.
Viewer FAQ
Where does What's Past Is Prologue sit in the The Flash guide?
S05E08 is listed hour 100 of 184 — hour 8 of 22 in season 5, season 5 episode 8.
When did The Flash S05E08 air?
What's Past Is Prologue aired 2018-12-04 and is listed at 60 minutes.
Do I need Arrow first?
It is the 2014 spinoff and the Arrowverse's bright counter-argument. Arrow context helps; Barry's STAR Labs family is built to welcome a first-time speedster fan.
In the series
Why this series still plays
Grant Gustin's Barry Allen is the Arrowverse's heart-on-sleeve counter-argument: superspeed, STAR Labs found family, Reverse-Flash timeline headaches. Villains of the week plus season-long speedster myth. Sincere broadcast heroics — the cheerful engine that made CW crossovers annual events and multiverse storytelling feel like Thursday-night sport.
The CW did not stagger this one. **2014** put Grant Gustin's Barry Allen on the Thursday ledger as the Arrowverse's heart-on-sleeve counter-argument, and the overnights showed up. Greg Berlanti, Andrew Kreisberg, and Geoff Johns: forensic scientist gains superspeed, builds a found family of metahuman allies at STAR Labs — Candice Patton, Danielle Panabaker, Carlos Valdes, Tom Cavanagh's Wells, Jesse L. Martin's Joe. Villains of the week plus season-long speedster myth. Reverse-Flash timeline headaches included.…
Filed against
- Grant Gustin as Barry Allen / The Flash
Grant Gustin's Barry Allen / The Flash was the Arrowverse's heart-on-sleeve counter-argument — superspeed, STAR Labs found family, Reverse-Flash timeline headaches, villains of the week plus season-long speedster myth. Sincere broadcast…
- Candice Patton as Iris West
Candice Patton played Iris West on The Flash — Grant Gustin's heart-on-sleeve Arrowverse counter-argument, STAR Labs found family, Reverse-Flash timeline headaches, villains of the week plus a season-long speedster myth. Sincere broadcast…
- Danielle Panabaker as Caitlin Snow
Danielle Panabaker’s Caitlin Snow steadied The Flash as STAR Labs science with a pulse — Grant Gustin’s heart-on-sleeve Barry, villains of the week, Reverse-Flash timeline headaches. Arrowverse found family in a Cortex. TV Flash files her…
- Carlos Valdes as Cisco Ramon
Carlos Valdes played Cisco Ramon on The Flash — STAR Labs found-family engineer, vibe as a later superpower, the joke that kept Grant Gustin's sincere speedster hour from becoming only a frown in a suit. Villains of the week, timeline…
- Tom Cavanagh as Harrison Wells
Tom Cavanagh multiplied The Flash as Harrison Wells — STAR Labs found family, Reverse-Flash timeline headaches, superspeed sincerity as the Arrowverse's heart-on-sleeve counter-argument. Villains of the week plus season-long speedster…
- Jesse L. Martin as Joe West
Jesse L. Martin’s Ed Green is Law & Order as the partner who made the dun-dun feel like a city again — ripped-from-headlines modular television with a badge that photographed as heat, not paperwork. Dick Wolf’s empire runs on cast churn.…