In order to increase his speed, Barry decides to travel back in time and learn from Eobard Thawne. Unfortunately, his actions draw the attention of a "time wraith".
Tropes:
- Aesop Amnesia: Barry apparently still hasn't learned that trying to impersonate a different version of yourself is a bad idea, despite his angst about getting Earth-2 Joe killed. His plan fails about as badly as last time, though (luckily) no one gets killed.
- Alone with the Psycho: When Thawne figures out that Barry is actually from the future (which doesn't take long), he wastes no time in knocking him out and handcuffing him within the Time Vault to question him. Barry comes very close to being killed multiple times, only managing to stop it through quick thinking and bluffing.
- Apologetic Attacker: Barry apologizes to his past self for neutralizing him.
- Arc Words:
- Thawne quietly says "Run, Barry, run!".
- Played for Laughs when Cisco mentions one of Season 2's Arc Words ("Doppelgänger") after seeing two Barrys. Future!Barry corrects him by saying, "No, not yet."
- Artifact Alias: Wells from Earth-2 gets angry when Barry calls Eobard Thawne "Dr. Wells" and asks him to stop doing it.
- Back to the Early Installment: Barry travels back to the Season 1 episode, "The Sound and the Fury", to learn the speed equation from Thawne.
- "Begone" Bribe: Thawne gives Barry the information he wants simply to get him (and the Time Wraith) out of the past.
- Berserk Button: Barry hits Harry's when he refers to Thawne as Wells, which causes Harry to explode that he's Wells!
- Big Damn Heroes: Hartley arrives at the last second to save Barry from the Time Wraith in the present day.
- The Bus Came Back: This episode takes place during the middle of Season One, so Eobard Thawne in the guise of Wells, Eddie Thawne, and Hartley Rathaway/Pied Piper all make appearances.
- Call-Back:
- Most of the episode happens during "The Sound and the Fury", and its events are dramatically altered so that Hartley Rathaway never escapes his cell.
- In "Fast Enough", Eobard Thawne was noticeably scared when he saw Jay Garrick's helmet. Ultimately, the goal of this episode is for Barry to learn from Eobard how to get faster to defeat Jay/Zoom.
- Call-Forward:
- Cisco's "What is it with you guys? It's like you think I have ESP or something. I can't just magically sense where things are." Not yet, but soon.
- Also, Cisco seeing Barry's updated logo before he makes it himself and musing about a Stable Time Loop happened "first" several episodes "later".
- Canon Discontinuity: Most of "The Sound and the Fury" is altered thanks to Barry's Time Travel.
- Can't Kill You, Still Need You: Barry pulls this on Thawne by creating an on-the-spot lie that he has a secret letter that will reveal Thawne's facade to his past self.
- Chekhov's Gun: When Thawne is talking to Barry in the Time Vault, the Reverse-Flash costume is prominently on display instead of being concealed within the wall as it was normally located in Season One and the Mercury Labs tachyon device which the Reverse-Flash had stolen is on it...the device (or a replica) that Barry was seen wearing in the Supergirl crossover. And the conversation they are having is Thawne telling Barry that tachyons are what he needs to increase his speed.
- Chronic Hero Syndrome: Barry interferes with the established timeline by stopping the Pied Piper from escaping from the Pipeline, basically ensuring that a majority of events in "The Sound and the Fury" never happened.
- Clock Roaches: Apparently Time Wraiths are a possible consequence of carelessly screwing with time travel.
- Close-Enough Timeline: The timeline Barry returns to. One major change is that the Pied Piper is now a friend and ally to Team Flash, and his parents appear to be re-establishing a relationship with him. Other than that, everything seems to be the same.
- Contrived Coincidence: The Time Wraiths are invulnerable to everything...except sound waves. Fortunately, the Villain of the Week Team Flash is fighting during this period happens to use exactly that.
- Cool and Unusual Punishment: Cisco inflicts Rick Astley on Hartley to get him to talk.
- Cosmic Retcon: Barry's Time Travel causes Hartley to be kept captive more easily and give him an opportunity to help Team Flash, thus setting up an offscreen Heel–Face Turn. Nothing else seems to have been affected...for the moment.
- Diabolus ex Nihilo: The Time Wraith. It just pops up out of nowhere to antagonize Barry (and everyone else in his vicinity) for his attempt at screwing with the timeline. It's never explained where Time Wraiths come from or why they're weak to Hartley's Sonic Stunner, and it's implied that Thawne isn't sure himself.
- The Dreaded: Not even Thawne likes the idea of fighting the Time Wraith.
- Didn't See That Coming: Barry is surprised by the Time Wraith, since Thawne never bothered to tell him about them when he was coaching him. When Barry confronts Thawne that he's never seen them before in his previous travels, Thawne merely replies that Barry's luck ran out.
- Enemy Mine: Barry and Thawne team up to stop the Time Wraith.
- Epic Fail: Barry's plan to get faster without raising suspicion bombs. Cisco writes down all the things to avoid alluding to or mentioning, as they won't have happened yet. Barry fails on most counts:
- No Earth-2 - Cisco accuses Future!Barry of being a Doppelgänger, to which he replies "Not yet".
- No breaches - Same as above, by extension.
- No time travel - Almost everything Future!Barry says or does implies knowledge of the future, or use of time travel:
- He tells Cisco to check Hartley's hearing aids for explosive capabilities, preventing him from escaping as he did originally. When Thawne quizzes him on this suggestion, Barry ineffectually dismisses it as a 'hunch'.
- He leaves his new model iPhone lying around - Caitlin just shrugs this one off, though.
- He's unusually indifferent to an alert at the CCPD, preferring to focus on the Speed Equation (which itself implies far more knowledge than Barry should have at that point).
- He demonstrates Phasing, when Thawne had not yet taught him this.
- He outright says "the Caitlin from the time I'm from" when discussing the tranquilliser dart Future!Caitlin made, cluing the rest of the team into the fact that Barry has the ability to Time Travel 4-5 episodes earlier than they previously learned this.
- The fact that the Time Wraith has appeared (and that he casually refers to having seen it before CCPD) clues Thawne into the fact that this Barry has time-travelled, and carelessly.
- Dad still in prison - This one he does avoid spoiling.
- No Jay Garrick - He avoids mentioning this as well.
- No suspicion that Wells = Reverse Flash - While he doesn't lead Cisco or Caitlin to this suspicion, Past!Wells quickly figures out that this Barry knows who he is, and almost murders Future!Barry, reasoning that doing so will not affect the past.
- No Ronnie / Stein - Once the facade falls, Future!Barry outright tells Cisco that Hartley knows where Ronnie is. Possibly a Justified rule-break, however, as by this point, he'd changed so many things that the original sequence of events that led Hartley to show Cisco what happened to Ronnie and Stein may not have happened, so doing this possibly helped preserve the timeline.
- "Eureka!" Moment: Wally saying that he reads the journals of famous engineers because he can't go talk to them gives Barry the inspiration to ask Thawne for help.
- Facepalm: Thawne has one when Past!Barry speeds into the Cortex and confronts Future!Barry.
- False Reassurance: Thawne lets Barry live in part because Barry revealed that Thawne's plan worked: He did force the Flash to help him get back to his own time. He just left out the part that Barry had smashed Thawne's time machine before the trip could actually happen and Eddie's Heroic Sacrifice ended up destroying his evil descendant.
- Fling a Light into the Future: Deliberately invoked by Barry when he gets Eddie to record a message to Iris on his phone (that Eddie thinks he's recording for Iris' birthday), which helps Iris deal with her feelings of loss a year after Eddie's death.
- Foreshadowing:
- The Time Wraiths seem to be important in future storylines for both this show and Legends of Tomorrow.
- Cisco has a vision of Zoom dangling some poor woman off a building (although it might have been Linda).
- The episode's plot is one for Season 3, especially the conclusion.
- Freeze-Frame Bonus: When present Barry and Future Barry are together and everyone is trying to figure out what is going on, present Barry tells Cisco about all the times they've watched The Wrath Of Khan together. Cisco points at future Barry and calls him an imposter. Then future Barry tells Cisco he always says Spock's line about friendship to him at the end of the movie. Confused, Cisco lowers his hand, but right before he does he starts to make the Vulcan V-shaped hand salute with his fingers.
- Funny Background Event: Thawne facepalming when Future!Barry and Past!Barry confront each other, then frantically gesturing for Future!Barry to shut up, then resignedly deciding the hell with it and just flat out stating that time travel is involved.
- Guile Hero: Future!Barry pulls an impressive bluff to stop Eobard Thawne from killing him, convincing him first that his plan worked and he got back home, then that Past!Barry will find a letter revealing everything unless Thawne helps Future!Barry.
- Heel–Face Return: Hartley's Heel–Face Turn is this to Barry (and to the audience), who still remembers the old timeline in which Hartley never became an ally of Team Flash.
- Heel–Face Turn: Barry's meddling with history causes Hartley to have made one of these some time in the past.
- Ignored Expert: Harry warns Barry that going back in time this far is a very bad idea, since Thawne will probably see through the facade. And man should Barry have listened to him.
- Idiot Ball: Barry grabs it by going back in time so Eobard Thawne - his Arch-Enemy - can help him solve the Speed Equation.
- In Spite of a Nail: Despite Barry's extensive meddling in the past, everything seems relatively unchanged upon his return except that Hartley Rathaway has pulled a Heel–Face Turn and is now on good terms with Team Flash and his family.
- Mirror Match: Barry fights his past self to neutralize and impersonate him.
- Mythology Gag:
- Barry's Cosmic Retcon made Hartley Rathaway pull a Heel–Face Turn, much like Hartley's comic counterpart.
- Barry sending a message from the deceased Eddie to Iris is reminiscent of how Barry gave Batman his father Thomas' letter from the Justice League: The Flashpoint Paradox.
- The speed equation that Barry writes out 3x2(9yz)4A is the speed mantra that comic Jesse Quick and her father use to tap into the speed force.
- Never the Selves Shall Meet: An important plot point. Future!Barry has to tranquilize Past!Barry so he can learn from Thawne how to get faster and beat Zoom. However, it proves tricky to inject Past!Barry and it ultimately wears off too soon, so the two Barrys meet after all.
- No-Sell: Thawne uses the fact that Barry didn't even blink when he stood and super-sped over to him, which should have utterly freaked out the Barry from his time, to deduce that the Barry he was talking to was from the future and already knew "Wells" was the Reverse-Flash.
- Noodle Incident: Thawne has encountered Time Wraiths before, but doesn't elaborate.
- Oh, Crap!: Thawne with the Time Wraiths. They're introduced in this episode and it's made very clear he's terrified of them. In the scene where he asks Barry why he didn't mentioned seeing one earlier, and in the later scene where he tells Barry that there are other speedsters and they always try to avoid Time Wraiths, it's clear he's close to panic and it's taking everything he has to keep it together.
- Out of Order: This episode takes place some time before Barry ends up in the world of Supergirl, but due to the series airing on different networks, the crossover aired the day before this episode.
- Percussive Maintenance: The drive that Thawne gives Barry seems to do nothing in the time vault console...until Barry hits it.
- The Reveal:
- Thawne tells Barry that there are other speedsters out there besides them. Of course, Barry already knows that by now.
- We also find out what makes the Reverse-Flash faster than Barry - tachyons, which boosts his speed in addition to helping him travel through time.
- Ripple-Effect-Proof Memory: When Barry returns to the present, he's surprised to see Hartley is an ally of Team Flash, as he still remembers the old timeline in which Hartley never became an ally.
- A Simple Plan: Barry intends to go back in time and arrive during the lull after Team Flash faced Pied Piper so he can ask Thawne how to get faster. Naturally, it all goes to hell.
- Say My Name: Thawne gets Barry to address him by his real name.
- Shout-Out:
- The Time Wraith's resemblance to a Dementor does not go unnoticed.
Hartley: Ho-ly Harry Potter.- Barry and Cisco have watched Wrath of Khan five times.
- Cisco compares the Time Wraith to the Grim Reaper apparition in The Frighteners.
- Skilled, but Naive: Thawne lampshades that Barry really doesn't know what he's doing when he time travels.
- The Slow Path: As Barry is leaving for the future and taking the Time Wraith with him, he tells Cisco and Caitlin that they have a year to figure out how to stop it. Seconds later (from his perspective), he lands back in his time and they shoot it with some gun Cisco made. It doesn't quite work, but Hartley shows up and uses his gloves to finish it off before it can kill Barry.
- Spanner in the Works: Future!Barry causes some massive hiccups for Thawne, but he just rolls with it. Eventually he just gives Barry what he wants so that he (and the Time Wraith that's after him) will leave.
- Spotting the Thread: Thawne is quickly able to figure that Barry time traveled due to him alerting Cisco about Hartley's explosives and writing out the Speed Equation. The Time Wraith just confirms it.
- Stable Time Loop: Cisco seeing Barry's new emblem several episodes early elicits the same reaction from him.Cisco: Suppose we now change your emblem. Will it be because we got the idea from this?
- Suspiciously Similar Substitute: The Time Wraith is a dead ringer for the Black Flash, the comics equivalent of a Grim Reaper for speedsters.
- Teeth-Clenched Teamwork: Barry and Thawne, since they both know the truth about each other and can barely stand each other.
- Tempting Fate: Barry naively asks "What could possibly go wrong?" before he time travels.
- Took a Level in Kindness: Whatever Barry did in the past caused Hartley to do this.
- Villainous Breakdown: Thawne has one, since he takes Future!Barry's existence as a sign that his plan failed (which he's absolutely right about). This almost leads him to Rage Quit and just kill Future!Barry right there, but Future!Barry manages to stop him with a convincing bluff that his plan actually worked, but there's a hidden plan-thwarting letter that Past!Barry will find if anything happens to him.
- Wham Episode: Barry's Time Travel antics cause Season One Team Flash to find out about Barry's time travel abilities quite early, and also cause the Pied Piper to turn good.
- Whole Episode Flashback: As the title suggest. The twist is that Barry literally time traveled to an earlier episode.
- Xanatos Speed Chess: Impressively, Barry holds his own with Thawne in the Time Vault.
