The Flash Season 4: Everything You Need To Know

Flash Barry Allen may have reached the 'Finish Line', but is this the end of your trip? It's not a bit of that. Our television screens will receive another injection of the Speed Force very soon when the Scarlet Speedster returns for another season of adventures.

Here's all we know so far about the Flash 4 season, starting with the most important question: when can we see it?

The launch season Flash 4: When will it be broadcast?

The CW has confirmed that The Flash will return to its schedules on Tuesday, October 10 at 8 / 7c.

As standard, Sky1 will play the game a couple of weeks later in the UK.

The launch of season 4 of Flash: Who will star? 

The following cast has been confirmed as returning next season:

Grant Gustin as Barry Allen / The Flash

Candice Patton as Iris West

Danielle Panabaker as Dr. Caitlin Snow

Carlos Valdes as Cisco Ramon / Vibe

Keiynan Lonsdale as Wally West / Kid Flash

Jesse L. Martin as Detective Joe West

Tom Felton as Julian Albert

Tom Cavanagh how?

You will notice that while the participation of Tom Cavanagh is confirmed, it is still about to reveal who will play.

The first season of The Flash was seen playing both Harrison Wells and Eobard Thawne / Reverse Flash disguised as Wells.

In the second season, Cavanagh played the doppelganger of Wells Earth-2, an irritable but good-hearted scientist, nicknamed 'Harry' to distinguish him from his predecessor.

The third season introduced another variant - 'H.R.' Wells from Earth-19 - but the chirpy novelist was murdered at the end of this year, 'Finish Line'.

In all probability, then, the fourth season will reintroduce Cavanagh as full-time Harry (the character currently resides on Earth-2) or introduce a fourth major version of the character of Wells.

'Finish Line' also saw Dr. Caitlin Snow depart Team Flash – the bio-engineer had been struggling to cope with gaining meta-human powers, losing control of her emotions and briefly turning to the dark side as the villainous Killer Frost.

By the end of the third season, Caitlin turned her back on her wicked ways, but didn't feel ready to return to S.T.A.R. Labs, opting to spend some time on her own away from her friends. What will her state of mind be, heading into season four?

The Flash season 4 episodes: What happens next?

Below is the official synopsis for season 4. It was released – notably – in mid-May, prior to 'Finish Line' airing. As such, it's pretty scant on detail (and actually contains some details which now appear to be out of date).

Barry Allen (Grant Gustin) lived a normal life as a perpetually tardy C.S.I. in the Central City Police Department. Barry's life changed forever when the S.T.A.R. Labs Particle Accelerator exploded, creating a dark-matter lightning storm that struck Barry, bestowing him with super-speed and making him the fastest man alive The Flash.

But when Barry used his extraordinary abilities to travel back in time and save his mother's life, he inadvertently created an alternate timeline known as Flashpoint; a phenomenon that gave birth to the villainous speed god known as Savitar, and changed the lives of Caitlin Snow (Danielle Panabaker) and Wally West (Keiynan Lonsdale) forever.

With the help of his adoptive father, Joe West (Jesse L. Martin), his lifelong best friend and love interest Iris West (Candice Patton), and his friends at S.T.A.R. Labs - Cisco Ramon (Carlos Valdes), C.S.I Julian Albert (Tom Felton), and an Earth-19 novelist named H.R. Wells (Tom Cavanagh) - Barry continues to protect the people of Central City from the meta-humans that threaten it.

Despite the synopsis naming H.R., it appears unlikely that the character will feature in season 4, having given his life to save Iris in 'Finish Line'.

The finale also left Barry in a precarious position. With the Speed Force having grown unstable, our hero decided to enter the energy field himself – as penance for having created Flashpoint – leaving his loved ones behind, apparently for good.

The next 23 episodes will have to start by bringing Barry back, with fans speculating that season 4 could tackle the Rebirth storyline from the comic books, just as season 3 adapted Flashpoint.

Here's a brief summary of what happens in Rebirth, and how it might relate to the TV series.

Warning: potential spoilers ahead!

Having returned from the Speed Force under mysterious circumstances, Barry is left with a lingering concern that he was not supposed to come back, and that the Force is trying to draw him back in.

Sure enough, it turns out that his return comes at a cost: he is becoming the new Black Flash, a Grim Reaper for Speedsters. Barry re-enters the Speed Force in an attempt to spare his friends and family, where he learns the true cause of his transformation – a resurrected Eobard Thawne / Reverse-Flash, who has infected him with a "negative Speed Force".

We'll stop there... but it's certainly possible that The Flash is heading in this general direction on television.

The show's currently down a Black Flash, with Killer Frost having taken out the previous holder of that mantle (Hunter Zolomon) in season 3's finale, while Reverse-Flash is currently deceased, having previously been taken out by Black Flash in Legends of Tomorrow's season 2 closer.

One thing we know for sure about season 4, though: at least one episode will be devoted to a four-way crossover with the show's sister series Arrow, Supergirl and Legends of Tomorrow.

"There will be a big fourth-quarter crossover with all four of the shows that are on in the fall," confirmed The CW's president Mark Pedowitz in May 2017.

The Flash season 4 villain: Who's the new Big Bad?

Before season 3 had even ended, it was announced that the following year would not feature a Speedster as the chief villain. Fair to say, after season 1's Reverse Flash, season 2's Zoom and season 3's Savitar, it's probably time for a change.

The Big Bad will be quick-witted rather than fleet-footed, with The Thinker – aka Clifford DeVoe – confirmed as season 4's main antagonist.

The news will not be a big surprise for fans of The Flash, since DeVoe has been mentioned - as a threat that Barry still had to face - by two time-traveling villains, Savitar and Abra Kadabra.

Although there are four different versions of the character, Clifford's DeVoe version of the Thinker is one of the most enduring enemies of Flash, having first appeared in All-Flash # 12, published in 1943.

A failed lawyer who believed he was a superior intellect to the criminal element, DeVoe began a new career as a "brain" for petty offenders, using a "cap of thought" that could project mental strength.