The Flash's timeline is about to change in a major way.
After Barry Allen (Grant Gustin) decided in the season-two finale to go back in time to save his mother Nora (Michelle Harrison) from getting killed by the Reverse-Flash (Matt Letscher) back when he was a child, he set in motion a chain reaction that will affect literally every single character on The CW's comic book series. When season three premieres, Barry will find himself living a new life in an alternate timeline, having to get used to his new reality.
So what does that mean for the DC Comics show's new season? The Hollywood Reporter rounded up everything you need to know before tuning in to season three.
Because of Barry's choice to change the past, he'll be living through a version of the iconic DC Comics storyline Flashpoint. The 2011 comic book crossover of the same name written by DC Comics boss Geoff Johns had consequences that reverberated throughout the DC Comics universe, leading the comic giant into a massive re-launch of its titles called "The New 52." The storyline was most recently brought to life in 2013 with an animated movie titled Justice League: The Flashpoint Paradox, which followed the Flashpoint story closely.
One of the biggest consequences of Barry going back to the night his mother was killed by the Reverse-Flash is the fact that Barry brought Eobard back with him to the present to ensure that his mother survived that night, meaning that in Barry's new timeline, he has Eobard locked up. His nemesis doesn't pass up the chance to taunt him from captivity either, asking him, "Now who's the villain?"
Other changes that Barry is going to have to get used to in the new timeline (which begins after a three-month time-jump) is that he lives with both of his parents who are alive and well, Joe (Jesse L. Martin) and Iris (Candice Patton) hardly know him and Cisco (Carlos Valdes) is the richest man in Central City and has no interest in getting to know Barry.
"This is something that is going to ripple throughout the whole season," says writer Todd Helbing says. "Obviously Barry grew up with a different family. His parents were still alive, Cisco has gone on to make some money. One of the [ripple] effects is [Arrow's] Diggle [David Ramsey] himself. You'll have to tune in to see exactly how."
But don't expect Barry and Iris to be a lost cause when it comes to a romantic relationship despite him erasing their entire lives together.
"In any timeline, Barry and Iris ultimately find each other," Helbing promises.
Kid Flash is born
Another major change to the timeline is the introduction of Kid Flash, aka Wally West (Keiynan Lonsdale) finally living up to his DC Comics destiny. He's Central City's version of the Flash and his nemesis is the Rival (Todd Lasance).
Double the villains
"We're doing a really cool thing this year. We're doing two big bads," Helbing says. "One is a speedster [named Savitar] and the other, the one in the creepy mask, is Doctor Alchemy."
While the actual identity of Doctor Alchemy is being cast at a later date, as of right now he is being voiced by Tobin Bell, the man behind Saw villain Jigsaw.
"He certainly doesn't like the Flash," says Aaron Helbing. "He's a bad dude and he's going to be a formidable adversary to everyone on the team throughout the season."
As for Savitar, the speedster comes straight from the DC Comics canon. After an accident involving a supersonic fighter jet and lightning gave him speedster powers, he named himself after the Hindu god of motion since he believed his newfound powers were a divine gift. Described as a "vicious and cruel man," he became obsessed with his new powers, and dedicated his life to studying velocity and pushing himself. He discovered many new powers that no other speedster had ever been able to accomplish like heal himself instantly and even protect himself with a force field. But the one thing he always craved was more access to the Speed Force.
A new work nemesis
As if Barry didn't have enough things to deal with already, he's also going to have some competition at work. Harry Potter alum Tom Felton joined the show as Julian Dorn, a fellow CSI at Central City Police Department who suspects there's more to Barry Allen than just his good guy reputation. And seeing as how Felton joined the cast as a series regular, that means he's sticking around for the entire season and Barry's work problems won't be going away anytime soon.
Later this fall, The Flash is finally going to get musical when it crosses over with Supergirl.
"Some of you may know my own personal love of musicals, and actors who have been in them. And we have a number of people who can sing, across all the shows, who'll be making some very exciting appearances in the back half of the year," says executive producer Greg Berlanti.
Since both casts feature extremely talented singers like Glee grads Gustin and Melissa Benoist, Broadway vets Jesse L. Martin and Jeremy Jordan as well as pop singer Carlos Valdes, the episodes are bound to be a hit, and the song choice potential is endless. To give you an idea of what to expect, Berlanti already teased the possibility of seeing Legends of Tomorrow star Victor Garber singing "Edelweiss" to Nazis.
Although the first crossover on The Flash this season will actually be Arrow's Felicity (Emily Bett Rickards) showing up in episode two. "She's giving Barry advice," Gustin says.
The big crossover
But the crossover that everyone will be talking about this season is the giant four-way crossover between all the Berlanti shows: Arrow, The Flash, Supergirl and Legends of Tomorrow. And when all of the Arrow-verse heroes team up, they will find themselves battling DC Comics alien race The Dominators.
"We're taking inspiration from a DC crossover from the late 1980s known as Invasion!, which featured an alien race called The Dominators, who'd previously vexed the Legion of Superheroes," says Arrow and Legends of Tomorrow executive producer Marc Guggenheim. "We're using cutting-edge prosthetics and computer effects to achieve a feature film-quality look which is faithful to Invasion! artist Todd McFarlane's interpretation of the characters."
In Invasion!, The Dominators - or Dominion as the race was called as a whole - were extremely technologically advanced, skilled geneticists and lived in a very strict caste system where your place in society was determined by how big of a red circle was on your head. The Dominators were very interested in the genetic potential of the human race, especially in the metagene, or the fictional biological variant that caused some humans to become metahumans.
The Flash season three premieres Tuesday, Oct. 4 at 8 p.m. on The CW.