After being killed at the barricade, they all wake up again and run from the place of their deaths, thinking they should hide from the repercussions. Eventually, they realize they cannot die.
Bahorel is the first one to die and the first one to wake up in a pile of dead national guards. When the guard realizes he's not dead, he gets sent to prison and then sentenced to galleys. He eventually tries to start a mutiny, it goes bad and he gets tossed in the sea. That's when he realizes he cannot die.
Jehan wakes up in an empty street covered in bodies, with his hands tied up and blood on the back of his neck. He panics, runs away, realizing he should be dead. He takes his new condition very seriously and tries to disappear.
Courf, Feuilly, Bossuet and Joly get tossed into a mass grave. They crawl their way out of it (probably dying a few times in the process) and go into hiding around Paris, where they reach the conclusion that, if they're alive, there's a chance their friends also are. So they start looking for them.
The first one they find is Bahorel, out of pure incompetence of both sides (but mostly on Bahorel's side). He's the most unsubtle anyone could be in his situation, picking up fights for fun, participating in riots, and all of that without leaving Paris. It doesn't take them long to find him after he returns from his accidental fake death in the galleys.
And that's pretty much it for a couple of years. They fucking need Combeferre, because they don't know how to keep searching. They periodically have meetings on the subject of "how to find Combeferre so we finally get a braincell"
Combeferre had gotten separated from them on the barricade. He died next to a door, and one of the ladies of the Corinthe pulled his body inside and nursed him back to life (literally). It doesn't take him much time to understand what has happened and he runs off to Praga, enroles in the university, and runs some tests on himself to better understand his new immortality. He isn't actively looking for the others, because he has no reason to assume they're alive, but eventually he starts picking up signs of their presence, and a suspicion starts to form. When he finally finds them, it becomes pretty clear to all of them that they had all probably survived.
Ăponine wakes up under a sheet in the backroom of the Corinthe. She immediately panics and runs away. No way she's staying around after that horrible love confession to Marius.
As years pass by, Musichetta realizes she's not aging. His boys, who had kept an eye on her over the years, notice it too. After a teary reunion with her old lovers who she thought dead, she's soon brought into the group.
Grantaire wakes up on the floor of the cafe, next to the corpse of Enjolras, massacred by bullets. He doesn't understand what's going on, but he hears some noise and shoots downstairs, so he kisses the corpse goodbye and runs away before they kill him again. He hides in Algeria and drinks to forget.
It takes Enjolras a lot of time to get back to life (eight bullets are a lot of bullets), and he has the bad luck of doing so just when the National Guard returned after killing the rest of the insurgents. Terrified of what they'd just seen, they lock him in a cell for years. When in the 1848 revolution the people opens the prisons, he escapes and leaves France and all his nightmares and guilt behind.
Enjolras spends a lot of time traveling, mostly around South America, helping with the independence processes. By the end of the century, he has helped fight more battles than he can remember, and he's currently settled in Cuba, fighting both Spain and the United States.
That's where he meets Grantaire, who had been on the island, drinking, for decades. After a mandatory fight, they decide to stick together because, god, it would be a lie to say they haven't missed their friends, and their narrative foil would have to do.
They never speak of their last moments at the barricade. Never.
However, time and nostalgia had sweetened the memories of the other. It doesn't take them long to remember that they can't stand each other, and their differences have done nothing but grow bigger in those years apart. They hate each other's guts, but can't stand the idea of losing sight of each other. That codependency grows to the point where they can't sleep without nightmares if the other isn't there. They still can't go a day without fighting. It's starting to get awkward.
Enjolras still travels around starting insurrections. Grantaire, of course, follows him. He even drinks a bit less. Or more, when he thinks about those first moments after first coming back to life, and the taste of the blood on Enjolras' lips. In his nightmares, he wakes up in his bed and Enjolras is not there. In Enjolras' nightmares, he wakes up at the barricade, and Grantaire never does. They still don't talk about the barricade.
Eventually, all their meddling in human history doesn't go unnoticed and Combeferre gets wind of them. He starts following their lead, and eventually finds them in the revolutionary Russia. Enjolras cries for three days in a row hugging Ferre when that happens, days that Grantaire spends completely wasted. He doesn't get sober until they find the others, and then it's his time to spend three days crying, hugged to Joly, Bossuet and Musichetta.
Even with their friends around, Enjolras and Grantaire's codependency doesn't go away. It will still take them years to figure out that in all that time together, maybe they have learnt to love each other.
They're almost all reunited at last, except for Jehan. They spend the next decades looking for him, with not a single clue of his whereabouts. After putting together legends, stories and rumours from all around the world, they finally find him in the deepest part of the Amazonian forest, hiding. They don't know if they should cry of happiness, yell at him or simply accept it.
And I guess at some point Courf and Bossuet keep track of Marius and Cosette's descendants, and Ăponine eventually shows up, but, who knows. Definitely not me.
