Spoilers ahead for Episode 19 of Gotham Season 4, called "To Our Deaths and Beyond."
Gotham has spent the last four years slowly but surely transitioning Bruce Wayne from the boy left crying in an alley into Batman. Given how Gotham has departed from every other Batman origin story, it has been impossible to guess what exactly would be the inciting event to kick off the final transformation into a Dark Knight. Even though Bruce recently got his first Batmobile and has been experimenting with vigilantism, he hasn't been twisted into somebody who would one day wear a cape and a cowl. The latest episode may have finally revealed the event that will mean the birth of Batman, and it came courtesy of none other than the resurrected Ra's al Ghul.
Resurrected with Bruce's blood earlier in the episode, Ra's retook the Demon's Head from Barbara and paid Bruce a visit at Wayne Manor to reveal that he respects Bruce for who he could become. Bruce obviously wasn't thrilled to be respected by a seemingly immortal madman like Ra's al Ghul, and he argued that Ra's has no idea what he could become. Then, Ra's revealed exactly why he's so sure about Bruce's fate, saying this:
I felt I owed you an explanation as to why I chose to live. When I took back the Demon's Head, I saw a vision of a cataclysmic event soon to befall this city. A cleansing fire that will destroy, purify, create. Create you, Bruce. Because I will use it as a might forge, molding you into a dark knight of Gotham. If it doesn't kill you, that is.
Given that Bruce Wayne is pretty much the one character who absolutely, totally, 100% can't die in Gotham, I think it's safe to say that this cataclysmic event will forge him into that dark knight rather than kill him. The episode ended on a flash back to Ra's' vision, which showed Gotham City burning, with people screaming in terror and/or pain. If what Ra's saw in his vision comes to pass, he wasn't kidding when he said a "cataclysm" was what's coming!
Now, normally, we might not take his words as proof that a cataclysmic event is likely to befall Gotham City. His dire prediction could have just been a tease for a crisis that will be averted at the last minute. I'm inclined to believe that Gotham may go all the way in destroying the city and forging Bruce Wayne into a person who is only a cape and cowl (and probably another growth spurt) away from becoming Batman, and it all has to do with what we know of the Season 4 finale.
The title of the Season 4 finale is "No Man's Land," which DC Comics fans everywhere recognized as the same name as the No Man's Land event that all but destroyed Gotham after a devastating earthquake. In the comics, Gotham is abandoned by the U.S. government and cut off from the rest of the world, forcing the Bat Family and what remains of the GCPD to try and fight back against the rising criminal underworld.
Now, in the comics, Bruce Wayne is already Batman for this arc, and he has help from the likes of Nightwing, Robin 3.0, and Oracle, not to mention other peripheral allies. Batman already exists, so No Man's Land had nothing to do with transforming Bruce into the Caped Crusader. Gotham may borrow key parts of the No Man's Land story and use them to create Batman. A TV take on No Man's Land could really be perfect for Gotham, as it would allow the show to continue balance Bruce's story with Jim at the GCPD and the various villains.
Ra's al Ghul may have just revealed how Bruce will become Batman, and it could mean great things for the audience, even if awful things for the folks in Gotham. Throw Jeremiah into the mix, and we have one big twisted party for Season 5, if Season 5 happens.