"Part of him is. He said it was like looking in a mirror, and he was right. But not just the way that he looked. It was... it was his eyes. The pain that was inside them. I've seen that in myself. When I think about how my parents died so violently. Sometimes I want to repay that violence with more violence. I wanna make someone else hurt as much as I do."
"But you don't ever do that. You're not him, you're a good person."
"I know, but it's in there, you know. That's in me. That power, that pain. That's where Savitar comes from. From loss. From losing you.
Barry Allen and Iris West on Savitar
"Cause and Effect" is the twenty-first episode of the third season of The Flash, and the sixty-seventh episode overall. It aired on May 9, 2017.


Barry takes drastic measures to stop Savitar. Meanwhile, H.R. continues to push Tracy Brand to design the trap for Savitar, and Killer Frost returns with an interesting proposal.[src]


Th episode gets right the latest relevant point of interest, current Barry and Savitar-Barry are seen having a conversation in the road.

Savitar uncovers he's a worldly peculiarity and a fast battle between the two breaks out, when it's uncovered the Savitar suit has its very own brain. Savitar and his suit in the long run make an escape and leave the scene.

Barry returns to STAR Labs and tells the remainder of the team the character of Savitar. The gathering begins conceptualizing ways on the best way to stop Savitar.

Iris approaches Barry and the two have a snappy conversation about what communicating with Savitar resembled. Barry advises Iris that Savitar was made from the torment that Barry has endured his life — the loss of his mom, the loss of his dad, and the loss of Iris. Cisco at that point surges in and discloses to them he has a thought.

Cisco shows Barry a machine he's assembled, one that will remove Barry's recollections. Among Cisco and Julian, the two clarify that in principle, deleting Barry's recollections should make Savitar stop to exist.

Cisco powers up the machine and Barry experiences a concise arrangement of his past recollections. After Julian asks how he's doing, Barry out of nowhere acknowledges he doesn't recall that anybody in the room, soliciting "Who are every one of you?"

Barry proceeds on a short befuddled digression, Julian and Cisco conclude that Barry is experiencing a type of amnesia.

Cecile calls Joe and notices that she needs Barry at the police office to help manage a crisis; Joe and Iris choose they'll take him while Julian and Cisco remain behind to take a shot at an answer.

HR strolls into the room where Tracy Brand is as yet taking a shot at the Speedforce trap and after a short second where the two almost share a kiss, they step back and proceed with work.

At the police division, Cecile examines a case wherein Barry needs to affirm for the arraignment and Joe clarifies the motivation behind why Barry can't affirm. With Iris and Barry off to get food, we see Killer Frost approach Savitar.

Savitar isn't reacting and when thumping on his suit, Savitar snatches her by her throat and pins her against the divider. It's uncovered that Savitar doesn't have the foggiest idea who he is, demonstrating that Cisco's amnesia machine worked.

Iris and Barry are having an espresso at Jitters when Iris imparts to Barry a portion of the pastimes he has, trying to get his recollections back. Iris clarifies her energy since it appears Barry is upbeat.

Barry gets called to the town hall when Cisco and Julian burst in and give Barry a couple of glasses. Barry is called to the stand and it's demonstrated that the glasses show the content that Julian kinds into a PC.

With Cecile addressing him, Barry responds to her inquiries, by means of the content Julian sorts into his PC. The glasses in the long run impede with Barry incapable to respond to the inquiries, the adjudicator excuses the charges against the respondent.

Back upon their landing in STAR Labs, Julian, Cisco, and Wally are met by Killer Frost, who appears to have removed Wally's forces. She reveals to them that she'll help get his capacity back on the off chance that they help her with something.

Iris and Barry are back at their place and Iris clarifies a few of the photos he's in. The two offer a kiss, which lights Barry's forces by and by and he zooms around their lounge before stumbling over the love seat. He asks Iris, "What just befell me?"

Iris and Barry head back to STAR Labs where they join the others and Killer Frost. Executioner Frost clarifies that the explanation that Wally lost his forces is on the grounds that Barry lost his recollections, causing a similar issue with Savitar, which rendered Wally's forces pointless.

Cisco, Julian, and Killer Frost go to work in the lab, when Cisco starts revealing to Julian an anecdote about how they functioned with Ronnie on the atom smasher. A troubled Killer Frost turns her back to the next two, at that point proceeds to complete Cisco's sentence.

Joe and Iris are trying Barry's forces when Iris makes reference to that she's never observed Barry this glad. She takes note of that despite the fact that this is an alternate variant of him, it's still Barry. Joe sets up a brief answer, contending that Barry has recently had 28 years worth of recollections and the memory-less Speedster isn't the individual they've come to know and love.

The man who got off free in light of Barry being not able to affirm — Heatmonger — starts to light a place of business ablaze. Barry choose he needs to go out and salvage the individuals stuck in the structure. On the scene, Cisco stuns Barry's cerebrum trying to kick off his mind trying to give him his recollections back.

Cisco understands that the "gas is in the tank," and they simply need to turn the start. Iris at that point jumps in the group correspondences framework and starts experiencing their past. Barry sees another memory montage, his recollections are back.

It slices to a fast scene with Savitar, his recollections are back now as well.

Presently with his forces back, Wally joins Barry and the two put out the workplace fire and put Heatmonger in handcuffs.

Back at STAR Labs, the individuals from Team Flash start testing Barry on little goodies just he'd know. He breezes through the assessment.

Executioner Frost starts leaving when Barry, Cisco, and Julian stop her. Julian notices that he can fix her, conceding he adores her. Executioner Frost chomps back saying that she doesn't cherish him, nor any of different individuals from the group. She leaves in the lift and for a concise second, we see her eyes switch back to Caitlin's, only for a second.

Iris notices to Barry about how she enjoyed him being glad for once and Barry makes reference to that the torment and haziness is just what his identity is. The two start kissing when HR strolls in, saying they need to come see something.

It's uncovered that Brand that has finished her Speedforce trap, however it's uncovered they'll require more force than what's accessible in the Sun. The scene closes with King Shark having been uncovered as the attendant of the force source they need.



Special appearance by

Guest starring




Promotional images



  • Cisco mentions the Star Trek: The Original Series episode "The Enemy Within" in which Captain Kirk is split into good and bad personalities.
    • H.R. mentions having Star Trek: Voyager on his Earth, to which Cisco claims to hate spin-offs. This is likely a tongue-in-cheek joke, considering the fact that The Flash is a spinoff of Arrow.
  • Cisco refers to Barry as "Steel Magnolia", referencing the 1989 film, Steel Magnolias.
  • After losing his memories, Barry asks to be called "Bart", a reference to Bart Allen, who is Barry and Iris' grandson in the comics.
  • Barry is revealed to have been a huge fan of anime in high school, with Iris mentioning that Dragon Ball Z was one of his favorites.
    • Coincidentally, this episode aired on the Japanese-recognized holiday "Goku Day".
  • Rather than "the Flash", Barry suggests that they call him "the Streak", a name which was first used to identify him in the first season of the show.
  • Mick Rory is mentioned at the CCPD as being "off the grid", indicating that the police do not know of his whereabouts. This alludes to Mick currently time-traveling with the Legends.


  • According to Barry's driver's license, it says that he renewed it on March 10, 2014. However, Barry was in a coma from the time of December 11, 2013 to September 2014, so he couldn't have renewed it during this time, assuming that it has to be renewed in person (unless a military member or dependent) like in real-life Missouri that Central City is placed in.
  • Tracy states they require 3.86 terajoules (3,860,000,000,000) of energy to power the Speed Force bazooka, which Cisco claims is more than the energy of the sun. This is vastly inaccurate, as the sun releases 384.6 yottajoules (384,600,000,000,000,000,000,000,000) of energy every second.
    • 3.86 terajoules is also less than the approximate output of a nuclear power plant running at full capacity for two hours.
  • As Savitar's armor begins to attack Barry, Barry's mask is removed. However, shortly prior to the armor stepping on Barry, his mask is seen back on his face.
  • Closeups of Killer Frost's forehead show an obvious line of about 5 mm below her hairline where there is no Killer Frost makeup, as it's not properly blended.
  • Even though Hartley Rathaway was seen to have made amends with Team Flash following the events of "Flash Back", Cisco refers to him as a "dick" in this episode.


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