In the Season 2 finale of "The Flash," Barry Allen changed everything. The ramifications of his actions will be felt in Season 3, which will adapt a well-known DC Comics event, and everything we've heard about the follow-up so far has major implications for Barry, his friends and Earth-1 in general. In anticipation for this world-shaking season of "The Flash," CBR breaks down everything we know (so far) to prepare you for Barry Allen's bold new world.

RELATED: Everything We Know About "Arrow" Season 5 (So Far)

Here Comes "Flashpoint"

After some speculation and a lot of teases, "Flashpoint" is finally here. On Twitter, "The Flash" star Grant Gustin confirmed Season 3 will kick off with its own spin on the major DC Comics event from 2011, which found Barry Allen trying to navigate a totally altered world where his mother Nora was alive.

This won't come as a major shock to fans of the show. After all, Barry sped back to the night his mother died in the Season 2 finale and stopped Reverse Flash from killing her, irrevocably changing his past -- and that's where the season ended. In the comics, Barry returns to the present to discover that he not only lost his powers, but transformed his timeline into a bleak world where Thomas Wayne became Batman and Superman was detained by the government his whole life, among other things.

In this new timeline, Barry encounters a brave new world where both of his parents are alive and Wally West is Kid Flash. Joe West will also be on the outs with his daughter Iris West because of unrevealed reasons, though she will still be a reporter. Barry will encounter Joe at a low point, and Barry will have to work hard to get Joe out of his rut.

"When we find [Barry], he's been in this timeline for three months. He didn't grow up with Joe... or Iris. They're kind of acquaintances. He's still a CSI," Gustin explained.

"Every character has different relationships with different characters, and that's a result of 'Flashpoint,'" added executive producer Todd Helbing.

"[Barry]'s starting to have new memories of graduating high school and college, memories he never had with his parents, but those memories are replacing other things from the other timeline," Gustin revealed.

"Barry is the only one that knows the timeline is different, and his memories are starting to get replaced from the previous timeline with new memories, like graduating high school and graduating college, moments with his family," he shared. "When he realizes those memories are replacing other memories, that's when he stars to realize how selfish of a decision this was and that maybe he should try to put things back the way they were."

"In the same sense that he's forgetting a lot of memories, it means he's forgetting his powers too," he continued. "It's like he's having a full 'Back to the Future' moment, where essentially his hand is disappearing in front of him."

According to Gustin, "[Season 3] is pretty 'Flashpoint' focused right now, which I think we are going to see the repercussions coming out of 'Flashpoint. There will be ramifications all season long from 'Flashpoint.'" However, that doesn't mean "Flashpoint" will remain in effect forever. "'Flashpoint' does not last all season long," he added. "But there are permanent ramifications."

The Rise of Kid Flash

flash-kid-flash

It's official: Kid Flash will arrive in Central City this fall. In July, The CW unveiled our first look at Keiynan Lonsdale's Wally West as Kid Flash, who makes his speedster debut in "Flashpoint," "The Flash" Season 3 premiere.

During the final episodes of "The Flash's" second season, Wally and Jesse Wells were both affected by a second particle accelerator explosion after Harrison Wells attempted to get Barry's speed back. Both were knocked out by the force of the explosion, but neither showed any speedster abilities before the season ended. However, it seems that will change when the show returns this fall.

"Kid Flash is a big part of 'Flashpoint,'" Lonsdale revealed at Comic-Con International in San Deigo.

"He's Kid Flash, so I try to play him with a real young, lighthearted cockiness to him," he shared. "He's in really good place mentally. He's never been more sure of himself."

"Wally is definitely in Joe's life," added Jesse L. Martin. "He's definitely Joe's son, but Wally's got a life that Joe knows nothing about." While Joe West will interact with Kid Flash, he won't know that the hero is his son, Wally.

A New Villain or Three

flash-savitar-e2cfb

Kid Flash won't be the only new speedster in Season 3 -- Savitar will also be making his live-action debut. Created in 1995's "The Flash" #108 by Mark Waid and Oscar Jimenez, the villain was central in the fan-favorite "Dead Heat" arc and went on to appear in Geoff Johns and Ethan Van Sciver's "Flash: Rebirth."

Though no casting has been announced for the character, Savitar will battle Barry Allen at some point in the show's third season. In the comics, Savitar was a Cold War-era pilot from a third-world nation whose plane was struck by lightning, giving him super-speed and a strong connection to the Speed Force. Naming himself after Savitr, the Hindu god of motion, the character studied elements of the Speed Force that were unknown to other speedsters at the time, eventually forming his own cult. Savitar developed the ability to create a force field, regenerate and transfer speed to other objects and people.

"Savitar is more of a psychological villain in a weird way," Todd Helbing said of the character. "I think the Hindu word for Savitar means God of Speed; he's all about speed. Everything about this guy is different. I can't go into super detail, but he's not like Zoom or Reverse Flash."

While Savitar will appear later on down the line, another speedster villain will be waiting for Flash when Season 3 opens. "Vampire Diaries" star Todd Lasance's the Rival will arrive in Central City just in time for the season premiere. In the comics, the Rival was Jay Garrick's dark mirror. His true name is Dr. Edward Clariss, and he was once a professor at Garrick's university. He attempted to recreate Velocity 9, the formula that gave Garrick his speed, and was somewhat successful; however, his formula has a cap to it and eventually runs out, so that he must continually take a dose in order to maintain his speed. Eventually, the Rival becomes pure speed force.

Initially, Lasance was reported to have been cast as Savitar, one of two "big bads" in "The Flash's" third season; however, executive producer Greg Berlanti quickly shut that rumor down on Twitter. Lascance will, then, likely play the black-clad speedster spied in "The Flash" Season 3 sizzle reel that debuted at Comic-Con International in San Diego.

This season will feature a "Flash" first: a non-speedster antagonist. At "The Flash's" San Diego Comic-Con panel, it was revealed that classic DC Comics villain -- and non-speedster -- Doctor Alchemy will be making his villainous debut this season.

"We're doing two big bads. One is a speedster, and the other is Doctor Alchemy," Todd Helbing explained.

In the comics, Doctor Alchemy is a scientist with multiple personality disorder who harnesses the ability of transmutation -- kind of like Firestorm -- using it to wreak havoc on humanity. He's made appearances on various DC Comics-based animated series, and most recently showed up in Geoff Johns, Doug Mahnke and Ivan Reis' "Justice League" #30.

As revealed in the same panel, Tobin Bell -- the voice of Jigsaw from the "Saw" films -- will voice one of these villains, though it's not clear which villain that will be at this time.

The Rogues Form Up

flash-rogues

In Season 3, the Rogues will grow their numbers with some new recruits. Previously, the series had introduced Captain Cold (Wentworth Miller), Heat Wave (Dominic Purcell), Captain Boomerang (Nick Tarabay), The Trickster (both Mark Hamill and Devon Graye), Golden Glider (Peyton List) and Pied Piper (Andy Mientus). In the comics, various groups of Rogues have frequently functioned as a team against The Flash -- there's no firm indication yet that'll happen on the TV show, but these new recruits provide further room to speculate on the possibility.

First up: Mirror Master. Grey Damon was recently cast as Sam Scudder on The CW series. He's set to appear in the fourth episode of season three, which should air in late October or early November. According to the character's official description, Mirror Master is "one of the Flash's most infamous Rogues. Sam Scudder -- aka Mirror Master -- is a smooth criminal with a huge ego. Upon discovering he now has the power to travel through any reflective surface, Scudder embarks on a massive crime spree to prove himself the greatest thief that Central City has ever seen."

Ashley Rickards' Rosalind "Rosa" Dillon, aka the Top, will join him in his new criminal venture. She "has the power to make people's heads spin... she's the Bonnie to Mirror Master's Clyde and one of the most dangerous members of the gallery of Rogues."

"Fargo" and "Independence Day: Resurgence" star Joey King will also debut as the classic DC Comics villain Magenta. Magenta will arrive in the third episode of "The Flash's" upcoming season, just one episode prior to Mirror Master and the Top's premiere. Considering the character's history in the comics as a founder of a new team of Rogues, it's possible she could join forces with other villains as the "Flashpoint" story arc shakes up the series in Season 3.

In the comics, Magenta (AKA Frances "Frankie" Kane) was an ex-girlfriend of Wally West who gained the ability to control metal, at the cost of becoming completely mentally unstable -- thus birthing the Magenta guise. Though she first appeared in Marv Wolfman and George Perez's "New Teen Titans," the character became more prominent during Geoff Johns and Scott Kolins' "Blood Will Run" arc on "The Flash."

Despite his apparent death in "Legends of Tomorrow," Wentworth Miller will return to "The Flash" -- as well as all of The CW's other DCTV shows -- this fall. The actor has signed a contract that will have him appear on "Legends of Tomorrow" and "The Flash," and potentially other DC TV series, in a recurring capacity.

"It's kind of the origin of Mirror Master...We're really excited," explained executive producer Aaron Helbing. Todd Helbing, his brother and fellow executive producer, added, "It's the origin story of him, but it's this struggle between Mirror Master and Captain Cold and you get to see who comes out on top."

A Trip to Lovely Gorilla City

flash-gorilla-city-cw

During the Television Critics Associations' summer press tour, executive producer Andrew Kreisberg confirmed that Gorilla Grodd will return in the upcoming third season of the CW drama -- but that's only the beginning.

"We're going to be doing a two-part episode that takes place in Gorilla City," he revealed during the network's panel.

The last time viewers saw Grodd was in the seventh episode of Season 2, "Gorilla Warfare." Thanks to a bit of trickery by Dr. Wells and Team Flash, Grodd was sent through one of Central City's breaches to a primitive jungle city on Earth-2 adorned with statues of gorillas.

In the episode, Wells explained that the settlement was a refuge for other apes that had been the subjects of scientific experiments, signaling the first -- but now we know not the last -- appearance of Gorilla City.

Introduced in 1959 in DC Comics' "The Flash" #106 (the same issue in which Grodd debuted), the hidden city in the jungles of Africa is home to a race of super-intelligent gorillas that gained their abilities from a meteorite.

Barry, The Eternal Optimist

Barry had a rough go of things in Season 2, but don't worry -- he won't lose his optimism in Season 3, at least according to Gustin.

"We won't lose it," Gustin said. "I will be adamant! I don't know what's going to happen in Season 3, how they're going to write it, where they're going to go, but [Greg] Berlanti and [Andrew] Kreisberg and Geoff [Johns] -- I actually don't know how closely Geoff's involved anymore -- but all those guys know 'The Flash' better than anybody, and they know that he has to have the optimism."

"He lost his mom at a young age, he saw her right in front of him, then went back in time and watched it again... he'll find a way to deal with this [his father's death]," he continued. "He's not going to let it ruin him. It's going to be hard to come back from this one, but he'll stay optimistic Barry."

Tom Cavanagh Will Stick Around

Tom Cavanagh is back -- again! The actor will be a season regular in Season 3, though we just can't be too sure who he'll be playing this time around.

Over the past two seasons of the show, Cavanagh has played two separate characters: in the first season, he was Eobard Thawne, aka Reverse Flash, masquerading in the form of Earth-1's Harrison Wells. In Season 2, he played Earth-2's version of Harrison "Harry" Wells. However, in the Season 2 finale, he and his daughter Jesse returned home to Earth-2 with the help of Earth-3's Jay Garrick.

Thanks to the events of the Season 2 finale, Cavanagh could be playing an entirely different character: the original Earth-1 Harrison Wells. In the finale, Barry upset time as he knew it, which means it's entirely possible that Reverse Flash never went on to murder Wells and his wife.

"I will say that it's enjoyable that by the time this season ends, if I get to play three different characters on the show, I can check that off my bucket list," Cavanagh joked at SDCC.

The Return of Jesse Quick

Like father, like daughter -- sort of. Jesse Wells will also return to "The Flash" for Season 3. While Violett Beane will definitely reprise her role as Jesse, it's unclear in what capacity. As Beane herself said, "[I] could be Earth-1 Jesse, [I] could be a speedster, who knows."

Nevertheless, she remains hopeful that Jesse will become a speedster in her own right: "When Jesse got hit [by the particle accelerator], I was like 'It's happening! It's happening!' There was the spark when she got out of the coma, but... it didn't happen, and I was like, 'No!' I'm very excited and would love for it to happen early next season."

Jay Garrick's Future

The Season 2 finale also revealed the identity of Zoom's man in the mask. As it turns out, he was none other than Earth-3's Jay Garrick -- and Henry Allen's doppelganger. The revelation was pretty rough on Barry, who had just lost his father, but -- fortunately for him -- the Flash from Earth-3 headed home pretty quickly.

John Wesley Shipp, who plays both Jay Garrick and Henry Allen, weighed in on the big revelation, saying, " "The fact that I'm now getting to morph into an entirely different character that is so important to the Justice Society of America, which also bleeds into 'Legends of Tomorrow,' he's such an important character to this whole world -- it just opens up enormous possibilities for me as an actor going forward, and the challenge for me, having played Henry, is that I now get to create an entirely different character going forward. And how that affects Barry -- because Barry's going to want to lean on this guy who looks just like his father but is not his father -- that can create a whole bunch of psychological conflict too. I'm as excited as you are to see how all of this will play out."

"Jay does not know the emotional minefield that he's walking into," Shipp added. "If I were to lose my father, and then there was someone there who looks just like my father, my impulse would be to want to go and get the same things from this guy that I got from my father. This guy's not going to know any of that, he's not going to understand it, so I hope there are those awkward moments where Barry tries to get from Jay what he got from Henry and it's not gonna be forthcoming, and they're going to have to make their own peace and form their own relationship based on the reality of what is. That opens itself up for all kinds of psychological possibilities."

"This character looks exactly like Barry's father but is tonally and attitudinally very different from Henry Allen, who was very available emotionally and much softer; very much a warm blanket for Barry when he was at his most vulnerable. That's not gonna be Jay," he continued. "Jay's a superhero, he's an original superhero, so he's not gonna know from all that."

Tom Felton Will Bring His Magic Touch

"The Flash" is bringing a little magic to Season 3. Tom Felton, who played Draco Malfoy in the "Harry Potter" films, weighed in on the big revelation, has signed on to play series regular character Julian Dorn, "a fellow CSI at the Central City Police Department who suspects there's more to Barry Allen than just his good guy reputation."

The character sounds similar to one described in an earlier report, which revealed that "The Flash" was looking to cast "Barry's slightly older, slightly geekier contemporary, a guy who is as smart as he is intuitive. As such, this newcomer doesn't buy Barry's nice guy routine and sets out to learn what he's hiding -- all while concealing some secrets of his own."

Felton's casting has been met with a lot of enthusiasm from fans. Felton thanked fans for the outpouring of support on his Instagram, writing, "Thank you for all your kind words today. See you in a flash. The Flash."

 

Aloha from a post office queue. Thank you for all your kind words today. See you in a flash. The Flash @cwtheflash

A photo posted by Tom Felton (@t22felton) on

At SDCC, Felton described his character Julian Dorn's relationship with Barry Allen as "slightly abrasive." He also said that, while Julian will know Barry through years of working together, Barry will not be familiar with Julian due to his newness in the Flashpoint timeline.

Kevin Smith: Back for More

Fresh off of directing "The Flash" Season 2 episode "The Runaway Dinosaur," Kevin Smith will be back for more in Season 3. Warner Bros. has confirmed that Smith will direct the seventh episode of Season 3.

Smith has also expressed a desire to direct episodes for "Arrow" as well as Marvel Television's "Daredevil." Just this week, he discussed how he would bring the supervillain Onomatopoeia to the small screen; he and Phil Hester introduced the character during their 2002 run on "Green Arrow." The masked villain was notable for the way that he spoke all of his sound effects and the graphic design elements that accompanied them. Smith said he would love to introduce Onomatopoeia on "Arrow," but he hasn't heard from the show's team about making it happen.

Of course, if "Arrow" doesn't work out, Smith figures "maybe I could do it on 'Flash,' or 'Legends of Tomorrow,' or now 'Supergirl' as well. There's a couple of shows there."

More on Caitlin's Background

Caitlin Snow has been a "Flash" mainstay since Season 1, but -- other than her romantic attachments and connections to the main cast -- the show hasn't revealed too much about her background. Season 2 teased a bit of her family life when she had a brief chat about her mother with Killer Frost, and the two women discussed how cold their mother was. Other than that, though, little to nothing is known about Caitlin's family life. However, all that will change once Season 3 rolls around.

"We haven't met Caitlin's mother yet. We got a little talk between the two women, which will probably play out in Season 3," teased executive producer Andrew Kreisberg.

True to Kreisberg's word, "Vampire Diaries" alum Susan Walters has since been cast as Carla Tannhauser, Caitlin's mother, who is described as a "world class biomedical engineer and CEO of a major research company." However, Caitlin won't exactly get along with her mother; she finds her mom "cold and withholding," while Carla thinks her daughter is "rebellious and ungrateful."

A Musical Crossover for the Ages

flash-supergirl-crossover

This spring, "The Flash" and "Supergirl" will join forces for a two-episode musical crossover on The CW, though this mini-event will be separate from the four-show crossover between "Arrow," "DC's Legends of Tomrrow," "The Flash" and "Supergirl," which is slated for November.

At the TCA press tour, executive producer Greg Berlanti confirmed the musical crossover and revealed that it will feature "mostly pre-exisiting" songs. However, he hopes to include at least one original song in each of the two episodes. Though no official date was announced, the crossover will air during the back-half of the season.

RELATED: "The Flash"/"Supergirl" Crossover: 10 Musical Numbers We Want to See

"We've got such talented actors, 15 years from now when the last of these shows is going off the air, that would be a big regret [if we didn't do it] – it's too much fun not to," executive producer Sarah Schechter explained.

"The Flash" star Grant Gustin and "Supergirl's" Melissa Benoist are both alums of "Glee," where they covered popular songs. Between the four shows, DCTV hosts a surprising number of musically-talented actors, including Jesse L. Martin, Victor Garber, Jeremy Jordan and John Barrowman, among others.

Supergirl and The Flash -- A Budding Romance?

When Barry crossed over into Kara Danvers' world for an episode of "Supergirl," the two had instant chemistry. From superpowered trips to the ice cream store to a race (of course), the two became fast friends over the course of the one-off story. Naturally, fans saw the budding of a romantic relationship between the two, and Gustin would tend to agree.

"It would be a good match," he said.

But not so fast, Grant! Melissa Benoist -- who plays the title character in "Supergirl" -- isn't too sold on the idea. "I don't know that they'd ever get together," she shared. "I think they're too similar... I think they're pals, pigging out on ice cream."

While an inter-dimensional relationship would certainly be difficult to maintain, "Supergirl" has made the jump from CBS to The CW for its second season, so that situation could very well change. Either way, it's looking more and more likely that the Girl of Steel will make her way into The CW's annual "Arrow"-verse crossover, so it wouldn't be entirely out of the question for the two to develop romantic feelings for one another.

This Year's CW Crossover Will Be Bigger Than Ever

With "Supergirl" joining "Arrow," "The Flash" and "DC's Legends of Tomorrow" on the network next season -- all shows under the purview of executive producer Greg Berlanti -- the time is ripe for a massive crossover of all four shows, and Amell predicts that the superhero team-up will air across one single week as a four-night extravaganza.

"I think what we'll end up seeing is one giant four-night crossover. This is kind of an unprecedented moment in terms of the history of network television. To have four shows [with the] same showrunner," he explained, referring to Berlanti.

Berlanti himself also weighed in on the crossover and teased what would bring the characters of these shows together. "I'm going to probably try to have one unifying threat, as opposed to different things on different ones, which is what the first year was," he revealed, adding that they're just starting the process of writing the crossover event.

"It's an external threat from outside the shows that will involve Supergirl coming over to 'The Flash,' then 'Arrow' then 'Legends of Tomorrow,'" executive producer Marc Guggenheim explained. What that threat might be, however, he did not disclose.

However, Amell draws the line at a musical crossover: "No. I'm out! I’m the first one. I get to draw the line, and I draw the line at musical."

Starring Grant Gustin, Jesse L. Martin, Carlos Valdes and more, "The Flash" returns to The CW on October 4 at 8 pm EST.