Marathon

Synopsis
After The Citizen prints an explosive story, Iris's life is threatened. Refusing to hide from those that are attacking her, Iris sets out to expose a dangerous organization. Meanwhile, Barry must face the consequences of the Crisis and fulfil Oliver Queen's wish for him.

Main/Featured Characters

 * Team Flash
 * Flash (Barry Allen)
 * Cisco Ramon
 * Frost (Caitlin Snow)
 * Joe West (first appearance)
 * Nash Wells (joins team)
 * Central City Citizen (first appearance)
 * Team Citizen (first appearance)
 * Iris West-Allen (first appearance)
 * Allegra Garcia (first appearance)
 * Kamilla Hwang (first appearance)
 * Cecile Horton (first appearance)
 * John Diggle
 * Gene Huskk (first appearance)

Villains

 * Black Hole (first appearance)
 * McCulloch Technologies (first appearance)
 * Joseph Carver (first appearance)
 * Doctor Light (Kimiyo Hoshi) (first appearance)
 * Maurice (first appearance)
 * Esperanza Garcia (first appearance) (mentioned)
 * Malcolm Strombard (first appearance)
 * Eva McCulloch (first appearance)
 * Sterling Brooks (first appearance)
 * Anthony Ivo (first appearance) (mentioned)
 * Anti-Monitor (mentioned)
 * Deathstroke (Slade Wilson) (mentioned)
 * Eden Corps (first appearance) (mentioned)
 * Eobard Thawne (first appearance) (mentioned)
 * Rainbow Raider (first appearance) (mentioned)
 * Remington Meister (first appearance) (pictured)
 * The Top (first appearance) (mentioned)
 * Zoom (first appearance) (mentioned)
 * Who's Who Binder
 * Abra Kadabra (first appearance) (mentioned)
 * Amunet Black (first appearance) (mentioned)
 * Arielle McAlpin (first appearance) (mentioned)
 * Block (first appearance) (mentioned)
 * Bug-Eyed Bandit (first appearance) (mentioned)
 * Dan Fisk (first appearance) (mentioned)
 * Derek Stricker (first appearance) (mentioned)
 * Dominators (first appearance) (mentioned)
 * The Mist (first appearance) (mentioned)
 * Girder (first appearance) (mentioned)
 * Grodd (first appearance) (mentioned)
 * Hotness (first appearance) (mentioned)
 * King Shark (first appearance) (mentioned)
 * Magenta (first appearance) (mentioned)
 * Trickster (first appearance) (mentioned)
 * Weather Witch (mentioned)

Other Characters

 * Bruce Wayne (mentioned)
 * Batwoman (mentioned)
 * Black Lightning (mentioned)
 * Felicity Smoak (mentioned)
 * Green Arrow (Oliver Queen) (mentioned)
 * Superman (mentioned)
 * Rip Hunter (first appearance) (mentioned)
 * Supergirl (mentioned)
 * Thea Queen (mentioned)
 * White Canary (mentioned)
 * Thunder (mentioned)
 * The Ray (first appearance) (mentioned)
 * Nora Allen (first appearance) (mentioned)
 * Hank Henshaw (first appearance) (mentioned)
 * J'onn J'onzz (mentioned)
 * Harry Wells (mentioned)
 * Jesse Wells (mentioned)
 * Pandora (first appearance) (mentioned)
 * The Monitor (mentioned)
 * Natalie (first appearance) (mentioned)
 * John Diggle, Jr. (mentioned)
 * Sara Diggle (mentioned)
 * President Marsdin (first appearance) (mentioned)
 * Allegra Garcia (Unknown Earth) (first appearance)
 * Legends (mentioned)
 * Obsidian Tech (mentioned)
 * Channel 52
 * Central City Police Department (CCPD) (first appearance) (mentioned)
 * Star City Police Department (SCPD) (mentioned)
 * D.E.O. (mentioned)
 * A.R.G.U.S. (mentioned)

Objects

 * Flash's Suit
 * Mirakuru

Locations

 * Earth
 * United States of America
 * Central City
 * CC Jitters (first appearance)
 * S.T.A.R. Labs
 * National City (mentioned)
 * Gotham City (mentioned)
 * Star City (mentioned)
 * Freeland (mentioned)
 * Metropolis (mentioned)
 * Happy Harbor (first appearance) (mentioned)
 * Lian Yu
 * Santa Prisca (first appearance) (mentioned)
 * San Monte (first appearance) (mentioned)
 * Gorilla City (first appearance) (mentioned)
 * Tokyo (first appearance) (mentioned)
 * Markovia (mentioned)
 * Dinosaur Island (first appearance) (mentioned)
 * Nanda Parbat (first appearance) (mentioned)
 * Fortress of Solitude (first appearance) (mentioned)
 * Kooey Kooey Kooey Island (first appearance) (mentioned)
 * Bialya (first appearance) (mentioned)
 * Zambesi (first appearance) (mentioned)
 * Qurac (first appearance) (mentioned)
 * Kasnia (mentioned)
 * Corto Maltese (first appearance) (mentioned)
 * Tunisia (first appearance) (mentioned)
 * Hong Kong (first appearance) (mentioned)
 * Earth-2 (mentioned)
 * Antimatter Universe (mentioned)

Trivia

 * Doctor Light made her first live action debut in this episode.
 * This episode reveals more of Nash's backstory.
 * On the board of the world map, we can see multiple location fron the DC Comics.:
 * Happy Harbor (the base of operations of the Justice League in the comics before the Watchtower)
 * Santa Prisca (a prison known for hosting Bane a Batman villain)