It's the most shocking reveal in the show's history.
First spinning off from hugely successful CW series 'Arrow', 'The Flash' has now gained legions of fans whilst standing on its own, and is currently hurtling towards the finale of its third season. One big reveal came in an episode broadcasted this week however, when the villainous Savitar was finally unmasked, marking one of the most shocking moments in the series' history to-date.
Grant Gustin stars as the titular hero in 'The Flash'
Barry Allen (Grant Gustin) aka The Flash has been going up against his most formidable foe yet, wondering exactly who was behind the Savitar identity but always coming a little short when it came to revealing the antagonist. That was of course until the latest episode, which saw the villain revealed to be none other than Barry Allen himself.
For a while now, the series has been unafraid of using time travel and different dimensions and universes, and it looks as if that theme is one that's set to continue with this reveal. Now that modern-day Barry realises he'll have to go up against and defeat a future and most-likely wiser version of himself, he's going to have to come up with something hugely inventive if he's to pull out a win.
Now Gustin will also be playing another role...
Executive producer Andrew Kreisberg has already described the character as "the darkest villain" in a chat with EW, adding that the idea of him being "a very damaged version of our hero was interesting and fresh to us."
He said: "To have our lead actor be both the hero and the villain isn't something we've done before, so that was exciting for us as storytellers."
Now the intrigue will of course turn to exactly how the writers are going to pull this complex story off. They know that the rabid base of fans who are extremely loyal to the series will be picking apart every move they make, so they've got to do something special.
What we do know about the future of the series however is that season 4 will have a villain who ISN'T a speedster, so it looks like Savitar's story is one that's going to be wrapped up before season 3 comes to a close.
More: Everything You Need To Know About 'The Flash'
'The Flash' continues Tuesdays on The CW in the US and on Sky 1 in the UK.