WARNING: This article contains SPOILERS for The Flash Season 3, Episode 21
Fans of The Flash are still reeling from the reveal that Savitar was the future Barry Allen, but thankfully, the next episode lays out in, perfect detail, exactly how Barry becomes the villain. Well, not exactly the Barry Allen that audiences know as the star of the show... and not exactly the future version of himself he met by traveling four years into the future. The truth behind Barry descending into darkness and becoming Savitar in the future - so that he could head back to the past - is both more complicated and a simpler story at the same time.
It's complicated in the sense that it involves more traditional time travel /causality/destined loops than The Flash has explicitly adhered to over three seasons. But if viewers are fans of popular science fiction films, TV series, or novels built on the same Terminator principles of time travel... putting the pieces together will be a walk in the park. Hopefully, with our help, fans will have a firmer grasp on the time travel at work in this villain twist than any before. In fact, this Savitar/future Barry Allen theory has been hinted at in a number of clues.
How Barry Became Savitar
"You will do everything you can think of — you’ll ever create time remnants of yourself, but he’ll kill them all, mostly. On the night of May 23rd, Iris will die in your arms… and it will break you."
The timeline re-writing and time travel behind Barry's trip into becoming Savitar is helpfully illustrated, as always, upon the S.T.A.R. Labs whiteboard - in this case, by Cisco Ramon. For those who recall Barry's trip to 2024, he set out to discover just how he and his friend managed to defeat Savitar (as they clearly had, since there was no mention of him in the infamous future newspaper in their possession). The results weren't as hopeful as expected, with the team disbanded, scarred, and broken. Savitar had been caught alright, but not before he killed Iris.
To accomplish the task, FutureBarry explained, he had even created Time Remnants of himself (traveling backwards a short while, and pulling that version forward) which Savitar had killed. Well... "mostly." That's the detail that sends the entire time loop in motion, with Cisco deducing that Savitar actually let a single Time Remnant of Barry survive. It was no accident, but the required Remnant that would survive beyond Savitar's imprisonment in the Speed Force, begin to come apart at the seams, and eventually realize its true destiny.
Tortured and abandoned, this Barry Allen Time Remnant would travel backwards through time into ancient history, building its reputation and legacy until acolytes were drawn to it as a god of speed - calling it "Savitar." Only then would he be able to have the revenge that destiny had already written for him. Revenge and, if he played his cards right, mastery of Time itself.
NOTE: Here's the wrinkle to keep in mind. Savitar moved his way up through history attacking speedsters and gaining their powers, but it seems that he visited the 2020 Flash before the 2016 Flash, only to be defeated and imprisoned. That future newspaper is likely the exact version of Barry's perfect future, in which he defeated Savitar based on his heroics. The fate pulling the strings behind Barry Allen's messing with reality in his 'Flashpoint' timeline is now up for debate... since it was that altering of history that created enough instability for Savitar to escape that very prison.
Once freed, Savitar could head backwards to torment the speedster who defeated him, explaining why Savitar knows that Barry Allen will trap him in a prison, because it's happened to him in the future already. As revenge, he travels backwards a handful of years to kill Barry's fiancée - creating a Barry desperate and broken enough to create the Time Remnant that would one day become Savitar.
Why Savitar Needs To Kill Iris West
For the sci-fi buffs, that closed loop of cause and effect is one of the simplest forms of time travel twisting. And as the rest of the team soon notices, such a loop of fate raises the most obvious question: which came first, Savitar, or the Barry Allen Time Remnant that eventually became him? In other words, if the real Barry has yet to produce a Time Remnant, couldn't he just... not do it, and stop the entire process? It's your classic Terminator form of time travel in which the things that will happen to change the past already have... now the current events are most likely locked on the path to creating their own history.
It's the kind of science fiction that only sounds complicated when you try to explain it, so fortunately, the evil Barry/Time Remnant/Savitar revealed at the end of the previous episode states it plainly for our Barry in the opening scene:
"I was broken and alone. I wanted the pain to end. And that's when I realized the truth, Barry: God feels no pain. All I had to do was become one. And I only need two more things: for Iris to die so that you are driven so far into the dark that I can be born... it may sound ironic given who I'm talking to, but I'll keep [the other] to myself."
That's as clear a perspective on Savitar's goal as can probably be offered. Savitar is fully aware of his true identity as a Barry Allen Time Remnant that this current hero has yet to create. Which means he's fully aware that he needs to play the role Savitar did for him, and kill Iris - beginning the cycle of torment all over again. That lingering second thing he needs is a curious twist. Even if Iris was killed, Barry could still stop the loop from continuing by... well, not get driven into the dark. Not create a Time Remnant in his efforts to defeat Savitar. Rely on his team to catch Savitar immediately, and he'd be without Iris... but without Savitar, too.
The Future Can Be Changed... Right?
It just would be The Flash if it didn't raise a batch of new questions even as it answered the old ones. There's a good chance that most viewers will be wondering the exact same thing as our Barry when Savitar explains the futility of his resistance: why can't Barry change the future that created this monster? Savitar is quick to respond in expected fashion, essentially driving at the idea of the Speed Force, the timeline, and reality itself as... imperfect, or inexact. And he uses one of the most heartbreaking, and now tragically futile moments in the show so far to explain it:
"Cause and effect's a tricky thing. Didn't work so well for Eddie, did it? Shot himself in the chest, Thawne's still kicking around. See that's the thing about time travel, Barry. The more you do it, the less the rules apply to you."
Fans of The CW's Flash associated characters on Legends of Tomorrow know that to be the case (exactly how the Time Wraiths or Black Flash factor in here isn't clear yet... though we suppose Savitar isn't actually "changing" anything). Maybe it's best not to take Savitar's word for it, since he's clearly unhinged and driven to achieve his goal by any means necessary (overlooking the fact that, if things go as destined, he'll wind up lock in a prison). After all, wiping Barry's brain means Savitar's memories never survived to that of the Time Remnant.
With that knowledge lost, he never began his loop of revenge in the first place. Which means Wally never got his powers in this timeline, and likely, several other reverberations and ripples of re-written fate. It's confusing, sure... but it may also be the door opening to show Barry and his team that the future can be changed.
The Flash airs Tuesdays @8pm on The CW.