The Flash Recap With Spoilers: Welcome to a Post-Crisis World in "Marathon"

The Flash is finally back from its midseason hiatus, making it the last of The CW's Arrowverse shows to return after "Crisis on Infinite Earths". Given how much time the series spent setting up the reality-shattering crossover, it was safe to assume that the series would be in a "brave new world" -- something that the midseason premiere quickly confirmed. Here's what you need to know about this week's episode, "Marathon". Spoilers for the episode below, obviously! Only look if you want to know!

***

Iris meets a man, Gene Huskk, who had previously worked at McCulloch Technologies for decades, only for a shady organization to infiltrate the company and steal a prototype gun. Iris asks for him to go on the record anonymously, and he agrees. He then tells her that the shady organization is called Black Hole. As he's telling Iris this, an assassin kills someone with the prototype gun, and receives her next target -- Iris.

Iris and the rest of the staff at the Citizen come up with a timeline for Black Hole's organization. Cecile, who is now the paper's legal advisor, questions if it's the right thing to do. Iris organizes a formal meeting with McCulloch's CEO, Joseph Carver, but does not expect him to give an official comment. Iris meets with Carver, who has taken over the company in the absence of Eva McCulloch, his wife. Iris confronts Carver about the gun, and he takes her to a secret part of the facility. Carver argues that Gene was paranoid and made up false information about Black Hole. Iris decides to run the story as is anyway.

Iris publishes the article, and is immediately sued by McCulloch for defamation. Cecile detects that something is wrong -- just as the assassin fires the gun through the Citizen offices. Iris decides to find Gene and make sure he's safe, and asks the rest of the staff to escape on their own. Iris finds Gene, but he is immediately killed by the gun. Iris grabs Gene's security clearance card and drives away, as the assassin slightly injures her.

Iris goes to Star Labs and figures out who the assassin is -- Kimiyo Hoshi, a new version of Dr. Light who went missing years ago. Joe confronts Iris about pursuing the story, and argues that defeating Black Hole won't happen overnight. Kamila, Joe, and Frost decide to organize a trap for Doctor Light, which ends up being a projection. Meanwhile, the real Iris confronts Carver, and accuses him of being the leader of Black Hole. Carver doesn't deny it, but accuses Iris of not knowing the whole story. Iris reveals that she's set up a dead man's switch, which will publish all of her information if anyone is killed. Dr. Light nearly kills Frost, but is called off by Carver before she can finish the job.

Later, Iris begins to suspect that Black Hole had something to do with Eva McCulloch's disappearance. She goes to McCulloch's building, and finds her way to Eva's old office. She investigates, before getting pulled inside a nearby mirror by a pair of hands.

Other tidbits from the episode include:

• Cisco stresses out about the fate of the post-"Crisis" Earth-Prime, and questions to Killer Frost if it was really a good thing. He reveals tat he's made a binder of the metahumans and villains that still exist on Earth-Prime. He then asks what Nash is going to do now that the multiverse is destroyed, and he reveals he's going to protect his underground bunker to make sure no one else wakes up the Anti-Monitor.
• Later, Cisco confronts Nash about his true intentions, and argues that he was selfish in helping destroy the multiverse. Cisco later watches a holocube message from Harry, and tells Caitlin that he feels guilty about not having used his powers to help prevent Crisis. Caitlin suggests that he uses his skills to help catalog the new post-"crisis" threats, even if that means him leaving Central City. Cisco tells Nash that he's leaving to explore Earth-Prime, and asks him to hold down the fort in his absence. As Cisco leaves, Nash takes a photo out of his bag, revealing him and an alternate version of Allegra on an adventure together.
• Barry arrives home with Diggle in tow. Diggle tells Barry and Iris that as part of Oliver's will and testament, Barry gets the mask that he first gave Oliver years ago. Barry inspects it and notices a bizarre smudge mark, and questions if its a secret message from Oliver. He enlists a reluctant Diggle in helping figure out what it could be. Barry finds sediments on the mask which match Mirakuru and Lian Yu's soil. Barry suggests that Oliver wants him to find the remaining Mirakuru before it falls into the wrong hands.
• They travel to Lian Yu and find no Mirakuru, which Barry gets upset about, thinking that he's failing Oliver. Diggle suggests that the sediment was from Oliver bringing his suit to fight Slade Wilson years ago, and that there isn't a mission to deal with, and that Barry should enjoy the new world that Oliver died for.
• Barry and Iris talk about how their emotions have fared post-"Crisis", and they both agree that they should slow down.

***

The Flash airs Tuesdays at 8/7c on The CW.