Wally West returns home for a visit, with a number of new Speed Force tricks at the same time Cisco returns home from Atlantis. Unfortunately, the joy of moment is short-lived after Wally reveals the real reason for his return: something is wrong with the Speed Force and he thinks Barry is responsible. Meanwhile, Iris' doppelganger continues her dark work as Nash discovers the source of his strange visions of other versions of Harrison Wells.
The Flash comics of Joshua Williamson (idea of Speed Force dying) and Mark Waid (Wally's new Zen Speed shtick is borrowed from Max Mercury)
The CGI of the helicopter in the first opening shot is clunky.
Cisco says that any doppelgangers who came to Earth-Prime from a Pre-Crisis Earth would be dead by now because of neurological degeneration, yet there are a number of alien doppelgangers living peacefully in National City in Supergirl, including an alternate version of Al the Bartender.
While part of me wants to laugh at how Barry seemingly doesn't find it all suspicious that Iris suddenly wants to live a normal life after she lectured him about not holding her back from living a life of danger as an investigative reporter instead of saying We Are The Flash, this is a rather glaring plot hole and it is weird that Barry doesn't notice the sudden shift in Iris' priorities.
Keiynan Lonsdale gets some of his best material ever as Wally West in this episode and rises to the challenge of making some potentially awkward speeches work.
The effects work of Wally dissembling the helicopter in midair is fantastic.
The lighting and music used to convey the warped Speed Force are fantastic.
The concept of the Speed Force dying seems to have been taken from the current run of The Flash comics written by Joshua Williamson, though the execution is quite different. Williamson's cosmology had the Speed Force being used to repel three other energies - the Strength Force, the Sage Force and the Still Force - whose existence somehow threatened the Speed Force and caused it to become less powerful.
Mention is made of Santa Prisca - the island nation where Batman villain Bane was born in the comics.
The opening scene where Wally dissembles a moving vehicle in order to slow its momentum and decrease the damage when it impacts is a classic Wally West stunt from the comics.
At one point, it seems that Wally has several time remnants helping him to disassemble the helicopter. In the comics, Bart Allen (aka Impulse) was able to create temporary clones of himself using the Speed Force. While it is uncertain that is what is happening here (it's possible we just see Wally moving so quick in such a short space that it looks like there's more than one of him) it's still a possibility worth mentioning.
Wally's new zen speed attitude seems to have been inspired by Max Mercury - a character Mark Waid created during his run on The Flash who was retconned to be an obscure earlier Old West speedster hero called Quicksilver who was published by Quality Comics. Waid's background had Max Mercury being the hero Quicksilver and then traveling through time erratically trying to bond with the Speed Force. Max had a different approach to his powers and he mentored the Wally West Flash in new ways to manipulate the Speed Force, similar to what Wally does in this episode.
Cisco is said to have just come from Atlantis, which now exists on Earth-Prime. It is unclear, however, if it is an above-ground island (as it was on Earth-2 Pre-Crisis) or if it is a sunken city as it usually is in the comics or the Aquaman movie.
Based on her single joint T-cell receptors, Barry determines that Maria Volkova was 110 years old when she died.
The kinetic energy level readings of Maria Volkova's body are almost 0, as if someone removed it all. This is how the new Turtle's powers function - by creating potential energy force fields which age people and objects in seconds by draining the kinetic energy around them.
Cisco reworks the Velocity-X formula into something that can speed-up Turtle II and neutralize her powers.
Cisco says that any doppelgangers who made it to Earth-Prime from the now dead Earths would be dead by now due to neurological degeneration.
Barry uses a tachyon enhancer to enhance his speed so he can physically enter the Speed Force
Wally: Barry, you don't get it! We are all connected! When I used to talk to the Speed Force, sometimes it would show me visions of different futures, different possibilities of how things could go. There was always one common thread; there was always a speedster that would pick up our mantles, like a chain of lightning stretching through centuries.
Wally: We can't punish ourselves for the mistakes we've made. That's a closed door. But we can take responsibility for our actions, no matter how great the obstacle to overcome.
Barry: Amala teach you that too?
Wally: No. You did.
Kamilla: Why is it every time I come to visit, all hell is breaking loose? (It's hard to say what's worse - the meta line or the muted delivery.)
Reference is made to Santa Prisca - an island nation which was on Cisco's map in 610.
The out of control helicopter is said to be on a trajectory to crash into the new Seaver Building. The old Seaver Building was blown up by Ragdoll in 505.
Wally has gained such fine control of his powers that he can shape the lighting generated by his aura. He demonstrates this by creating a lotus flower - a symbol of purity and renunciation.
Wally is confirmed to have joined the Peace Corps, since leaving the crew of The Waverider.
Wally is continuing to study Buddhism under Bhikkhuni Amala - a Buddhist nun assigned to his camp in the Peace Corps.
Eva is able to use her control of the mirror to show Iris Wally's reunion with her family. It strains her to do this for more than a minute.
Iris says that she's been trapped in the mirror dimension for weeks at this point, but it seems longer.
Eva says that her husband used to come to her mirror every day to try and find a way to get her out before he stopped coming. She says she isn't sure if he just forgot about her or decided to move on.
Eva says she hasn't touched her husband in 72 months, which is 312 weeks, which is 2,190 days.
The fake Iris is shown to go blank and mirror Eva's shaky hands as Eva fixates on repeating the phrase "2,190 days."
Cisco returns, having just returned to Central City from Atlantis.
Atlantis exists on the new Earth-Prime, much as it was confirmed to exist on Earth-2 in 205 as an above-ground island in the middle of the Atlantic ocean. It is unclear based on Cisco's description in this episode, however, if Atlantis is above the sea level or a sunken city, as in the DCEU.
Atlantis smells like fish and the smell tends to stick to your clothing, even after leaving it.
Nash moved into the office across from Cecile's new office in the same office building as Ralph Dibnt's detective agency and the Central City Citizen's offices. He is apparently noisy and continually distracts Cecile from her work, which has her now working nights.
Barry suddenly trips while trying to clean up after the party using super speed. When Wally asks if this is the first "hiccup" he's had with his powers, Barry recalls the flare up he had during 613 and his slowed healing in 611.
Wally says he feels something wrong with the Speed Force.
Wally learned how to send his consciousness into the Speed Force. Barry says he has done this before, but it usually comes to him and he sees it as his mother. Wally recalls this from 323 but says for him it is more like he hears a voice directing his actions but he hasn't heard the voice in months.
The Russian woman Wally saved from the helicopter crash is killed by a woman named Frida who seemingly stops time around her and then drains all the life out of her body, leaving a dried-out corpse behind once time restarts.
The Russian woman is formally identified as Maria Volkova - a Russian socialite.
Maria's killer is identified as Mrs. Frida Novikov aka Turtle II.
Like the original Turtle from 210, Frida has the ability to drain the potential kinetic energy from those around her, seemingly slowing down time. Frida has the additional power to generate focused force fields that drain all the potential kinetic energy from a person or object, causing people to age to death in seconds or objects to rot or decay, like the helicopter from earlier in the episode.
Frida Novikov was part of a drug ring in Central City. She was caught by Joe West and deported back to Russia.
Cisco heard several stories about Turtle II while traveling the world and came home to Central City hoping to learn more about her.
The Mandaorian is apparently a series in the Arrowverse as Nash refers to Cisco as the Ciscolorian.
Nash asks Cisco if he say any alternate versions of people he knew while traveling around the Earth.
Cisco says it would be impossible for anyone from the alternate realities to have survived.
Nash and Cisco get into a fight when Cisco refuses to drop work on Velocity-X to help Nash with exploring the possibility of doppelgangers surviving the Crisis.
The Iris mirror clone tells Wally about the fight Barry had with the Speed Force in 607.
Cisco picked Kamilla up a state-of-the-art camera from Quimby Labs in Germany. She uses it to take a picture of Iris and Wally.
Iris tells Camilla to delete the photo, as they shouldn't be putting pictures of newspaper employees anywhere Black Hole might be able to find them.
Wally takes Barry into The Speed Force and they determine that it is dying.
Wally says that the Speed Force sometimes gave him visions of the future and he saw the heroes who followed after him and Barry, including Nora West-Allen and his own children and grandchildren.
Wally refuses to take Barry back into the Speed Force.
Nash is attacked by a spectral figure with glowing red eyes like the Reverse Flash.
Barry uses a tachyon enhancer to enhance his speed so he can physically enter the Speed Force
It is revealed that Barry killed the Speed Force by exposing it to the power of The Spectre in A808 when he had Oliver Queen help him get into the Speed Force to go back to the dawn of time to battle the Anti-Monitor.
The Speed Force forgives Barry for his actions, since they were necessary to save the universe.
From what Wally can tell, he and Barry have a residual amount of Speed Force energy contained within their bodies, but once that power is gone, that's it.
Maria Volkova was one of two CCPD informants who led the police to Frida Novikov. Joe has the other informant in protective custody, figuring Turtle II is out for revenge.
Caitlin calls Cisco out on not asking for help working on the Velocity-X counter to Turtle II's powers and suggest she work on it while he go talk to Nash.
Wally finds Barry in the time vault.
Barry tells Wally how The Spectre's power killed the Speed Force.
Wally forgives Barry for what he did and apologizes for losing his temper.
Turtle II ambushes Joe West at CCPD headquarters.
A news story visible while time is frozen notes that fish stocks are at the lowest level of the decade.
Cisco is attacked by the Reverse Flash in Thawne's body. Fortunately, Thawne cannot access the Speed Force.
Cisco is saved by Cecile, who surprises Thawne with a stun-gun while he is strangling Cisco. She sensed Thawne's hatred from across the hall.
Caitlin completes the new Velocity-X formula.
The fastest route between STAR Labs and the CCPD Headquarters require Barry and Wally phase through the Central City Public Adjusters office.
Barry is able to distract Turtle II while Joe injects her with the Velocity-X formula.
Barry tales the Iris clone about how he killed the Speed Force. She tries to comfort him by saying it isn't really his fault and that maybe they could have a normal life.
Thawne, in Nash's body, is contained in The Pipeline. He says he wants to kill Barry, his family and his friends in that order.
Thawne says that he felt the Speed Force die and that once Barry has lost his speed completely, he'll make his move.
Wally leaves to move to the next Peace Corps project . Before he goes, he tells Joe that there's something wrong with Iris.
Barry decides to build his own artificial Speed Force, like Thawne did when he created the Negative Speed Force.
Kamilla realizes that the Iris clone is fake after looking at the picture of her she took through her new camera's viewfinder.
Kamilla is shot by the Iris clone with the mirror gun is apparently sent to the Mirror World.
The Speed Force.
All of Cisco's adventures traveling the world over the past few episodes, most recently having traveled to Atlantis.
The Boomerang Factor
It seems really weird that Wally thinks something is off about the Iris clone but Barry seems totally clueless his wife has been replaced by a doppelganger.
The Bottom Line
A rather lackluster episode which treats what should be major events - the death of the Speed Force and the return of the Reverse Flash - as relatively minor subplots compared to Barry and Wally fighting and Turtle II. There's way too many subplots and the best thing I can say about this episode is that the Iris clone (who is even more annoying than the original) was largely absent from it.