This episode starts where the last one left off. Barry is, understandably, brooding a bit. He talks to Iris about how the article that used to bring hope and a sense of purpose now only brings despair. Iris reminds him that if the article can change, so can the future. Barry wants to time travel and checks it out.
Ramsey is meeting with someone about more dark matter. The person attacks him and whatever took over Ramsey’s arm attacks the guy, who subsequently dies.
Cisco gives Killer Frost a nanothermite camouflage cocktail that he got from Ray Palmer so that Killer Frost is just a tad less intimidating and can be around normal people. Cisco and Ralph then take her to an art show where Camilla’s photographs are being featured. Killer Frost is not impressed, and Camilla is a little hurt.
Cecile and Joe talk about a murder case. Allegra Garcia has been in and out of prison for years, mostly for petty crime. She has the ability to control radio waves and is accused of killing a man while trying to hijack his car. It appears to be an open and shut case until Cecile meets her in the judge’s chambers. Cecile doesn’t think Allegra did it and arranges for bail with a dampener.
Barry is going to December 11th, the day after he will supposedly die. He also managed to make a mobile Gideon. He isn’t able to get very far, because he runs into a disruption barrier that hurts his leg. Iris and Gideon help him. The disruption barrier is made of antimatter and the primary expert on antimatter is Jay Garrick.
Barry pops over to Earth 3 to talk to him. Jay has been detecting antimatter signatures all across the multiverse and is supportive of Barry’s plan. There is no way to send Barry’s body through the barrier, but they might be able to send his mind. Jay has been working on a neural hyper collider, but he needs a speedster in his prime. Oh, and he’s now married to Dr. Joan Williams, the doppelganger of Barry’s mom. The writers definitely believe in soulmates.
Cecile tells Iris and Camilla about Allegra. Ralph, who is across the hallway, chimes in with a lead. The man was dead before he lost control of the car. He has burn marks that are not consistent with radio waves.
Iris and Ralph go to talk to the eyewitness. It’s a short talk, because he’s dead. And Allegra is standing over the body. They say that they just want to talk, but she lets out a burst that burns Ralph. Joe catches her.
Barry will be wearing Jay’s helmet in order for the neural hyper collider to work. He sees S.T.A.R. Labs explode. He sees Ralph, Killer Frost, and Cisco in his Vibe outfit die. He sees Iris die. According to Jay, he’s seeing billions of timelines at once. He sees himself disintegrate and they pull him out.
He’s unconscious and does not wake up to Lady Gaga. Joan reads poetry to him, specifically William Knox’s “Mortality,” which contains the title of the episode. The title also refers to the comic where Barry originally died in Crisis.
Barry is in a lot of pain when he wakes up. It’s called neural entropy and he will be in pain for a couple of days. He then tells them that he thinks the Monitor was right and he wants to see Iris.
Ralph has a sunburn. What Allegra hit him with was pure ultraviolet radiation. If he wasn’t a meta, it would have killed him. It’s part of the same electromagnetic spectrum as radio waves, so it makes sense that she would be able to control them too.
Allegra talks to Joe. She’s changed her tune and now says she didn’t do it. She wants to be a reporter and was investigating. Joe doesn’t believe her.
Cecile and Joe talk. Cecile thinks that she knows who killed both men and doesn’t trust them enough to tell them. Joe thinks that she’s doing the wrong person’s job.
Despite protests, Jay and Joan did move Barry to his apartment to see Iris. It’s Iris that tells Joan that she is the doppelganger of Barry’s mother. After they leave, Barry and Iris talk again. He’s less optimistic this time. The only timeline where everyone else doesn’t die is the one where he dies. She thinks that he’s given up and she doesn’t understand. She then leaves.
Joe comes by a little while later asking for Iris. Since she’s not around, Barry looks at the case file and then they have one of their lovely father-son talks about the coming Crisis. Joe tells a story about a time when he was a beat cop and almost died. His badge and Barry’s emblem are symbols of strength and duty. Sometimes they are called to make sacrifices, but that isn’t giving up. It’s resilience.
Cisco talks to Killer Frost, who was supposed to be watching Chester but got distracted drawing. She’s about as bad as I am. Cisco explains to her that it’s great to express yourself but to remember that everyone else is trying to do that too.
Cecile tells Allegra that she’s a metahuman too and Allegra starts to talk. She wasn’t alone when the particle accelerator exploded. Her cousin was there too, but she died.
Or maybe not. Ralph and Iris found out that she was taken out of juvi in a vegetative state by some shady organization. She’s alive.
She’s mad too. She shows up at the police station looking for Allegra. She fries everything and starts beating people up. Joe starts shooting. Cecile tries to get Allegra out.
Iris and Ralph call Barry. She says that Ralph can handle, but Barry’s not about to let that happen.
Barry shows up just in time to save Cecile and Allegra from “Ultraviolet,” as she calls herself. He then gets a wallop because ultraviolet light travels faster than he does. Gideon suggests a retreat, but he hears Joe’s voice in his head. He runs into her blast and makes it far enough to knock her out before he collapses.
In the infirmary, they talk about what really happened. Ultraviolet was trained as an assassin by a shadowy organization, killed the guy in the car and the eyewitness, and then planned to kill Allegra so that no one could prove she was still alive.
Killer Frost bought some of the art from the art show. Cisco puts her drawing up beside it.
Joe and Cecile talk. She wants to be a defense attorney for metas. She thinks it’s the best use of her powers and she has the perfect way to start. She got Allegra an internship with Iris.
Iris walks in on Jay and Joan checking on Barry. After they leave, her and Barry talk again. He would never choose to leave her, but if dying is the only that everyone lives, he won’t shy away from it. They need to tell the team.
Ramsey is doing a biopsy of the dead guy. His blood has coagulated with an unknown substance. When Ramsey takes out some of the substance to test it, THE GUY SITS UP and begins to attack him.
There were a lot of threads in this episode, more than I expected, but it’s good that they are planting seeds for Post-Crisis shenanigans. 8/10