basically what convinced me that sandor is the gravedigger on the quiet isle is the fact that when brienne describes sansa (and let’s be honest it’s a super general description) the elder brother instantly knew who she was talking about and he even says her name real quiet and surprised
like how else would he have known sansa stark from that bare bones description if he hadn’t been talking to sandor clegane, the guy who mentions her every five fucking minutes
The other thing that cinched the deal for me was EB mentioning in his soliloquy about Sandor that even his driving force (vengence against his brother) was taken away from him in the end. It doesn’t fit the timeline at all. When Sandor & Arya meet up with Polliver and the Tickler at the inn, one of the men mentions that Gregor is on his way to KL (for the fight with Oberyn). But Arya leaves Sandor on the banks of the Trident the very next day and the EB finds him shortly after. How could Sandor have died and been buried there within a day or two of being injured and still know about Gregor’s death? It would’ve taken Gregor time to travel from the riverlands to KL and then a few weeks more to die from the poison on Oberyn’s spear and then even more time for word to reach the Quiet Isle. Sandor Clegane is alive and well.
Mmm. The global timeline someone did on Westeros.org says Oberyn & Gregor’s duel was several weeks before Arya and Sandor met Gregor’s men at the Inn, but that has always made little to no sense to me and I figure he did his math wrong somewhere. Especially if you consider that Gregor’s men at Harrenhal should have been informed of his fate in the trial much earlier than a small island refuge for penitents.
Though, actually I should compare AFFC Cersei IV (where she tells the Small Council Gregor is dead). Hmm, that timeline has it at 3/8/300… and Sandor dying is at 2/9/300… so that settles that, then. There’s no way the Elder Brother finding a dying Sandor could have told him that Gregor was dead. Poisoned, perhaps, and dying, but not dead. (Note per that timeline Brienne arrives at the QI a month after Cersei makes her announcement, so that at least makes sense.)
But yes, the EB recognizing Sansa immediately from a very brief description is the biggest giveaway, really.
All of the things in the chapter where Brienne goes to the Quiet Isle, from the description of how to cross the water to the island to every single thing Septon Meribald’s dog does since the dog is introduced (I promise that dog has very little purpose in this story except to be a call back to Sandor) to Stranger to the Elder Brother’s back story to the Elder Brother in general to actually showing a big huge limping guy with his face suspiciously covered, are like white-hot exclamation marks that he’s still alive.