We all know The Last of Us is a great game (unless you're a hipster, or an Xbox fan boy). A lot of us want The Last Of Us to get a sequel.
Now this whole Marlene and the fireflies idea keeps coming up, but is there any truth to it? Well first let's look at where this rumor started. It started with an article on MoviePilot, by a blogger named Kenny Mcdonnell (not to be confused with Kenny McCormick from South Park) the article suggested that the next Last Of Us game, tell the origin of Marlene, and her militia group called the fireflies. However that article was his opinion (as this one is mine) and not really meant to be taken as fact. A cite like MoviePilot is meant for fans like me and you, to discuss our favorite games and movies, that's why anyone can make content on this cite, so anyone can get there opinions out there. However, don't confuse opinion with fact. Just because someone says they want the next Last Of Us game to be about Marlene, does not mean it will be about her. Neil Druckmann (the actual creator of The Last Of Us) has stated that they were "working on ideas for The Last Of Us with new Characters, ideas for The Last Of Us with Joel and Ellie, ideas for a Sci Fi game, and ideas for a fantasy game". That is all that is actually official about The Last Of Us 2.
WARNING: This next part is speculation.
With that quote (from the guy who actually made The Last Of Us) it's more likely that we would get a continuation of Joel and Ellie's story, than a prequel about Marlene, (that is if we get another Last Of Us game at all, they could very well make that Sci Fi or Fantasy game). If they do go with another last of us, it would be either a true sequel, continuing Joel and Ellie's story, or a new character. That means it's a 50% chance we get more Joel and Ellie, and a 50% chance we get a different story. Now a different story could be about Marlene and the fireflies, but the fireflies are only one group in the game. A new story could just as easily be about the origin of the hunters, or David's group, maybe they could tell us the story of why Tommy left the fireflies, or it could be about Ish, and what happened to him in the sewers, it could be about Sam and Henry, or they could even do something with Bill, or they could just tell the story of someone else entirely. At most the chance of Marlene getting an origin story is about 7%. That's not even taking into account the fact that Joel and Ellie are fan favorite characters, even The head of Sony has said that he "would like to see what life is like for these characters after the events of The Last Of Us". Now some bonehead out there is most likely going to say "these characters doesn't necessarily mean Joel and Ellie". To that I would say, first of all,
and second of all, when someone is referring to a work of fiction and says "these characters", unless they state otherwise, they are usually referring to the characters the story focuses on, (in this case Joel and Ellie). Also the fact that while some believe Joel and Ellie's story to be done (and many don't) Marlene's story is done, she was shot in the face, and is dead. You can't get more "done" than that. (which makes it pretty funny when people say, "psh, Joel and Ellie's story is done, but that dead girl over there, she's got more to tell"). Plus Marlene's not that great of a character. She's overly pretentious, and basically views herself as a god, she would be a hard character to root for, and would turn many fans away. The whole rising up against an oppressive government story has been done many times before, and having a character who is as irritating, and full of herself as Marlene taking the helm, would make it much worse.
It is possible for them to make a prequel about Marlene, but all things considered, it is very unlikely.
Most likely, the next game we'd see Ellie take the lead, while Joel sort of takes a back seat. It would probably take place a few years in the future, with Ellie in her late teens to early 20s.