In the wake of Barry Allen's disappearance into The Speed Force several months earlier, it has fallen to Iris West, Kid Flash, Vibe and Joe West to keep Central City safe from hostile metahumans. When a new armored villain - a flying samurai - threatens to destroy the city if The Flash doesn't show his face, the rest of the team go behind Iris's back and make a risky decision to try and rescue Barry, seeking out an apparently-recovered Caitlin Snow to do so. However, the Barry Allen they retrieve is not the same one they lost...
The Flash: Rebirth by Geoff Johns (the title), The Flash #180-181 (characters of The Flying Samurai and The Samuroids) and The Hitchhiker's Guide To The Galaxy (a character suggests an unlikely means of deciphering a secret message only to get a seemingly useless answer.)
Cecile says that Barry was found on "the 112 outside of Ivy City", 300 miles away from Central City. This seems like it could be a flubbed reference to Ivy Town - the suburb where Oliver Queen and Felicity Smoak lived during the time between Season 3 and Season 4 of Arrow and where Professor Martin Stein met his wife back in the 1970s, according to the first season of Legends of Tomorrow.
Where did Caitlin get the cold gun from? (Maybe Cisco finally had time to build a second one?)
Honestly, the only thing that makes this episode work as well as it does is the performances of the ensemble cast, particularly Danielle Panabaker and Carlos Valdes playing off of one another.
The special effects on the sequence where Kid Flash chases Peek-A-Book look amazing.
The episode opens with a quick recap of the last season of The Flash. It conveys the following scenes - Barry proposing to Iris, Caitlin declaring she needs to go away for a bit to figure out who she is following her transformation into Killer Frost, Joe West telling Cecile Horton he loves her and The Speed Force Storm threatening Central City until Barry goes into The Speed Force to fill the gap left by Savitar's non-existence in The Speed Force Prison.
The episode also opens with a special narration from Iris instead of the usual one from Barry.
Iris notes that Peek-A-Boo is teleporting to every third tower, guessing that her eventual target will be The Broome Tower. This is a nod to John Broome - a prominent comic book writer of the Golden Age and Silver Age, who is most famous for his co-creation of Hal Jordan - the second Green Lantern. Broome also had a lengthy run on The Flash, during which he created several key characters including Kid Flash, Captain Boomerang, Elongated Man, Abra Kadrbra and The Reverse Flash.
The Flying Samurai is a character from a relatively obscure Flash story which started in The Flash #180 (June 1968). The Flying Samurai was revealed to be one of several samurai-themed robots called Samuroids who were the minions of a Baron Katana .
The DCTVU Samuroid is eventually revealed to be under the control of The Mechanic and The Thinker.
Vibe addresses The Flying Samurai as Mifune and later calls him Kurosawa. These are nods to actor Toshiro Mifune - perhaps the most famous Japanese film actor of all time - and director Akira Kurosawa, who directed several films in which Mifune portrayed a samurai.
Vibe also calls The Flying Samurai "Samurai Jackass." This is a riff on the classic cartoon Samurai Jack.
Vibe says "Great Ceaser's Ghost!" at one point. This exclamation was also the catch-phrase of The Daily Planet editor Perry White in the Superman comics.
Cisco and Caitlin both make reference to the novel The Hitch-hiker's Guide To The Galaxy, with Cisco suggesting that Barry's message may hold "life, the universe and everything" and Caitlin asking if Barry's ramblings mean "The answer is 42."
Vibe makes mention of Danville. This is a suburb of Centeral City in the original Flash comics. It was a middle-class resident suburb, where Iris and Barry lived upon getting married.
Caitlin's newfound ability to control her powers and Killer Frost personality are apparently because of someone named Amunet, for whom she was working by working at the bar where Cisco found her. This is likely a reference to Amunet Black a.k.a. Blacksmith.
First appearing in Flash: Iron Heights (August 2001), Blacksmith was a villain who ran a black market for super-villains in Centeral Ciy. Briefly married to the super-villain Goldface, Blacksmith stole his formula, which gave him super-strength and a golden glow and used it herself. It left her with the ability to bond metal to her body and control any metal around her.
Clifford DeVoe a.k.a. The Thinker first appeared in All-Flash Comics #12 (September 1943), created by Gardner Fox and Everett E. Hibbard.
A District Attorney in Keystone City, DeVoe froze up while questioning a witness during his first big trial against the crime boss Hunk Norvock. Driven to drink by his failure and the realization that crime COULD pay, DeVoe went to Norvock and offered his services as "a thinker" - a fixer who could use fake alibis and obscure legal precedents to help Norvock and his men get away with anything. DeVoe would come to take over the gangs of Keystone City, who elected him as their new boss after DeVoe's cleverness allowed him to survive several attempts on his life including an attack by Boss Norvock himself.
Brought to justice by The Jay Garrick Flash, DeVoe sought revenge, outfitting himself with various bits of advanced technology. Chief among these was his "Thinking Cap", which increased his already considerable intelligence as well as giving him the powers of mind-control and telekinesis. Reforming in later years, he became friends with Jay Garrick before he died peacefully of old age. Unfortunately, a new Thinker - an artificial intelligence based on the brainwaves of a younger Clifford DeVoe - would go on to become an enemy of the Wally West Flash, The Justice Society of America and Cyborg.
The character of The Mechanic seen in this episode is a new creation, unique to the DCTVU. It is worth noting, however, that the name of The Mechanic has been used by other DC Comics properties, most famously in an episode of Batman: The Animated Series which focused on Earl Cooper, the man responsible for designing and building Batman's cars.
The Mechanic was also one of several British superheroes to appear in the Paul Cornell/Jimmy Broxton Knight and Squire (2010) mini-series. A character called The Mechanic was listed among the membership of the criminal gang The Average Joes in Batman Incorporated #6 (June 2011). The Mechanic was apparently the code-name of one of The Huntress's enemies on Earth Two, in the Pre-Crisis DC Comics Universe. Finally, The Mechanic was the code-name of Thomas Hague - a telekinetic member of the superhero team The Shadow Cabinet in the Dakotaverse.
The Quark Sphere is a device which is filled with Barry Allen's unique genetic marker, programmed to track his DNA using the electrical current of The Speed Force. Used in tandem with The Speed Force Bazooka, The Quark Sphere will trick The Speed Force into thinking Barry is still there once The Speed Force Bazooka pulls Barry out of it.
Shock results from a drop in blood pressure. Barry's instability is neurological in nature, according to Caitlin.
Schizophasia is a neurological condition where a person assigns the wrong definitions to words.
A sliced fibula would be severe enough an injury that Caitlin would amputate if the victim were anyone but a speedster.
Cisco suggests that the code Barry is writing in is a poly-alphabetic language like Greek, where the symbols are a unique alphabet rather than a mono-alphabetic substitution cipher.
Iris: My name is Iris West and I was supposed to marry The Fastest Man Alive... but six months ago he left. I promised him I'd run. So that's what I've been doing these past six months. Running as fast as I can.
(Cisco drinks the drink Caitlin made for him.)
Cisco: Oh, this is good! Is there anything you can't do?
Caitlin: Move on, apparently.
(Pokerface by Lady Gaga plays. We see an unfocused shot from Barry's point of view, looking at the ceiling. Caitlin and Cisco are standing above him.)Caitlin: Are you sure this is appropriate?
Cisco: Yeah. It's a good luck charm. I mean, it worked before.
Caitlin: Last time he was in a coma - not a pan-temporal extra dimension.
Cisco: Well... waking up to Gaga shouldn't seem too freaky...
(We see one of the Samuroid robots having it's face replaced by a woman. This is The Mechanic.)
The Mechanic: The Samurai served his purpose.
Unseen Man: As in 12th Century Feudal Japan. A time when the military class was powerful. The execution methodical. Like ours.
(The Mechanic moves to a touch screen and pulls up an image of that day's newspaper in Central City, reporting on The Flash's return.)
The Mechanic: Well, it worked. The Flash is back in Central City.
Unseen Man: It appears things are going as planned.
The Mechanic: As if there were any doubt.
(A chair turns around. We see a figure with a metal cap wired to his head sitting in it. This is The Thinker.)
The Mechanic: What's our next step?
The Thinker: I'm thinking...
The villain Vibe and Kid Flash are fighting at the start of the episode, the teleporter Peek-A-Boo, last appeared in 122.
Vibe's control of his power to create controlled breaches within a single dimension seems to have improved considerably over the past six months to the point that he can follow along behind Kid Flash with little effort. He is also able to use his powers as a tractor beam to hold Peek-A-Boo in place and force her through a breach.
The CCPD is now armed with special taser guns that Joe West is able to use to neutralize Peek-A-Boo.
Iris has taken over the leadership of Team Flash, organizing the team from STAR Labs while Joe, Cisco and Wally are in the field.
Iris says that 1 out of every 3 fights with a metahuman criminal they've had in the past six months has ended in the villain escaping.
Cecile Horton is in the process of moving in with Joe West.
Julian Albert has moved back to London. Joe has apparently been covering for Barry's absence for the past six by telling Captain Singh that Barry was on a sabbatical in the Czech Republic. With two CSIs out, the CCPD Crime Lab is woefully backed-up.
Joe refers to HR's funeral in 323.
Wally West can speak Japanese.
Cisco reveals he has been consulting with several people on a way to free Barry from The Speed Force. These include Harry (i.e Harry Wells, The Harrison Wells of Earth Two), Tina (i.e. Dr. Tina McGee of Mercury Labs), Tracy (i.e. Tracy Brand, who helped build The Speed Force Prison in Season Three), Felicity (a.k.a. Felicty Smoak a.k.a. Overwatch) and Curtis (i.e. Curtis Holt a.k.a. Mister Terrific.) He claims to have been working on the problem for over six months, since the night Barry entered The Speed Force.
Cisco is able to track Caitlin by Vibing her. She's apparently restored herself to normal and is "just Caitlin" again but has been working as a bartender in a rough bar in Central City rather than returning to STAR Labs for some reason.
Caitlin has two doctorates and a PhD.
Caitlin reveals that she somehow learned about Barry going into The Speed Force.
Iris makes a reference to a Mockingbird Satellite that Cisco has to pull up to track The Flying Samurai.
Cisco sets up his rig to removed Barry from The Speed Force at the old Ferris Aircraft facility where they first tested Barry's powers in the first episode.
Joe forgives Caitlin for everything she did to him and Cecile as Killer Frost.
Cisco and Caitlin calibrate The Speed Force Bazooka from 322 to pull Barry from The Speed Force.
Barry makes two references to "Nora (his mother) shouldn't be here during his rantings when the rest of Team Flash first see him. The rest of Barry's dialogue suggests he is experiencing moments in time out of sequence, with Barry saying something about not killing anyone as if speaking to a judge, asking if everyone can hear the stars singing, that someone told him the city was safe and there would be no residual danger but that wasn't true, saying the stars are melting like ice cream, that the stars are loud, that he and his dad are going to be okay, that he's not sure he can be like Oliver (a nod to his conversation with Green Arrow in the pilot) and various bits of rhyming nonsense along with a speech about revolutionizing how physics is looked at.
Barry also writes on the walls of his cell in a strange code.
Barry's neurotransmitters are functioning at five times normal speed.
Caitlin theorizes that Barry either developed schizophasia or dementia as a result of his time in The Speed Force.
Cisco plays Pokerface by Lady Gaga while trying to revive Barry. This is the song that was playing when Barry awoke from his coma in the first episode.
Caitlin uses a cold-gun like the one stolen from STAR Labs by Captain Cold to knock out Barry.
Wally attempts to impersonate Barry by wearing his costume and vibrating his face while fighting The Flying Samurai.
Cisco's translation of Barry's scribblings comes up with the phrase, "This house is bitchin'!".
Wally can heal a sliced fibula in four to five hours.
The delirious Barry says to Joe "You said it yourself. She goes looking for danger." - a line he said once about Iris to Joe.
Joe West has apparently rediscovered religion since dating Cecile. He has come to believe that "Strength means nothing without faith.". Iris is amused by this, saying that Joe hadn't attended church since she was a child.
Joe West is apparently a practicing Catholic.
Cisco made Barry a new bright red suit over the past six months - one exactly like the one worn by the future Flash in 319.
Barry is now capable of moving faster than ever before - even faster than Wally West.
Barry has no idea how he sensed that Iris was in danger. He says he has no memory of anything after he entered The Speed Force.
Caitlin rejoins Team Flash.
Caitlin returns to the bar she was working at and tells one of the men there to tell Amunet that she is out. The man responds violently which causes Caitlin to transform into Killer Frost. Frost says something about having fun while he can before Caitlin changes back to her normal self. Judging by her reaction, Killer Frost's attempts to take her over again are not supposed to be happening.
Iris couldn't bring herself to sleep in her and Barry's bed alone over the past six months.
The Samuroids were the work of The Mechanic, who we see with The Thinker in the episode's final scene.
Barry is recovered from "the 112 outside of Ivy City" - a town 300 miles away from Central City.
Iris, Joe, Wally and Cisco spend six months trying to keep metahuman crime in Central City under control.
Caitlin is able to reassert herself at some point within the past six months, apparently putting herself into the debt of someone named Amunet.
The Fridge Factor
It really does not make a damn bit of sense for Iris to be opposed to Cisco trying to bring Barry out of The Speed Force and it only seems to happen so there can be one more bit of forced drama between the team members.
For all of the confidence Iris built in the last six months, it seems a damn curious message that she should force herself into the damsel-in-distress role as some means of "saving" Barry.
Once again, Caitlin's character arc for the season is built around her inability to control her power.
The Boomerang Factor
Kid Flash and Vibe are dumbed-down to make Peek-A-Boo a threat in the opening sequence, with the whole "duck duck" scene.
The Bottom Line
Easily the weakest Season Opener to date on The Flash. Most of the ensemble is useless outside of a few brief character moments and The Flying Samurai isn't an engaging enemy. The Barry/Iris relationship continues to be less engaging and well-developed than literally every other romantic relationship on the show, despite it getting the lion's share of the screen-time. What's worse is that the episode is honestly trying to make Iris into a stronger character but still requires her to become a hostage in order for Barry to be able to function. Between that and them reviving the idea that Caitlin can't handle her powers without being corrupted, there's a lot of disturbing implications in this episode.