Ezio comes to in a cell, tired and angry and cold. His weapons are gone, and he has no idea how long he's been out. Long enough to start aching from the cold floor, but then- that doesn't take as much time as it used to. He stands up, stretching a little to work the stiffness from his muscles, and startles as he hears someone cough behind him. He has assumed he was alone in the room, but when he looks around, there's a man in a white hood on the ground near the door. He's never met the man before, but he recognizes him instantly.
"Altair?" The man nods, so Ezio asks, "What are you doing here?"
"I wish I knew," Altair says, a trace of a frown on his face. His words come out carefully, like someone speaking a language he doesn't know well, and Ezio can see traces of golden lines glowing on on his face beneath the hood of his robes. It's a strange sight.
"What's wrong with your skin?"
"It's the apple," Altair says. He had been sitting on the ground up until then, but now he stands and comes within a few steps of Ezio. "I've had some practice with it lately- enough that it can translate for me when I need it- but it does look strange. And translation alone isn't much help- I can't get it to do more. Maybe with practice..." He shrugs, and draws back one sleeve so Ezio can see the pattern of lines there. It does look a lot like what he remembers of the apple.
"How does it feel?" Ezio asks. He remembers Desmond mentioning Altair's strange relationship with the apple, but this is his first time seeing it in person. "Does it hurt?"
"Not at all," says Altair, and abruptly changes the subject, pulling his arm back and letting the sleeve fall again. "What are you doing here?"
"I-" honestly, Ezio had come chasing the tale of Altair's library, but he feels strange saying it to Altair's face. Altair is much younger than Ezio has always imagined him to be. "Came looking for knowledge," he finishes, lamely.
"But you found templars," says Altair.
"I always seem to," Ezio grumbles.
Altair turns to the door, and a moment later Ezio hears footsteps coming toward the cell. "Can you get away from them?" Altair asks.
"Probably," Ezio says. "But I'm not sure where to go after that." Masyaf is isolated, and this is his first time in the ancient building.
"Don't worry," Altair says. "Just get away from them. I can't help you with that, but I know the castle well. I can show you a way out."
"Alright," Ezio says. The footsteps stop outside the door, and Ezio hears the scrape of a key in the lock. Quickly, before they can come in, he asks, "Have you seen Desmond lately?"
Altair glances at him very briefly, and then says, "No."
"Oh."
"But I think he's dead."
And with that grim statement, the door swings open. Ezio lets himself sag against the wall, putting on a show of weakness he knows the templars will believe. They want to believe they've defeated him, and he knows he looks old. He is old, and tired- but that doesn't mean he can't fight anymore.
They tie his hands, lead him roughly from the room, to a place where a bald templar waits with a noose. The other templars push Ezio toward him, and he stumbles a little. The bald man leads him onto a wooden platform, noose still in hand, but Ezio isn't worried. The rest of the templars are quite a ways behind the two of them, and he likes the odds better this way.
Out of the corner of his eye, he can see Altair walking out on a second wooden plank, careful to keep Ezio and the man with the noose in sight. An eagle cries, and the templar pulls down Ezio's hood. He feels the noose pulled tight over his neck-
He turns, and strikes.
He will not die today, and as he fights, he tries to put every ounce of this conviction into his movements. He cuts a path through the templars, most of them too confused by his unexpected movements to strike back, and ahead of him he sees Altair start to run.
When he was younger, he would have given anything to be here, fighting templars alongside the man who had reinvented what it meant to be an assassin. He can't pretend that he's not a little excited by it now. The two of them scale the side of the keep, and it's not long until Ezio runs across the weapons the templars took from him- one of his hidden blades is broken beyond all hope of repair, but he straps it on anyway. It's one of the few things he still has from Leonardo, and besides, he feels unbalanced without it. There's a sword, too, and he takes that- and then Altair is urging him onwards, and they run again.
A few times they have to stop so Ezio can take care of the templars in their way, but before long Altair comes to a stop in front of a stone statue of an eagle. "What now?" Ezio asks.
"The ground below here is thin," Altair says. "And below that is water." He glances down at the statue, and Ezio understands.
"Thank you," he says. Before Altair can say anything in reply, he fades away, leaving only Ezio, a dozen angry templars, and a leap of faith.
-/-
...I'm honestly pretty sure the reason Revelations is my least favorite game is because it starts out with Ezio seeing Altair's ghost, or whatever it is, at Masyaf, and then it's never mentioned again. That could have been a really cool thing to explore. :/
Also, on a more story related point, I want to point out the difference between what the apple can do to Altair, and what Altair can do to the apple. In Rome, it's the apple inside Altair, reacting to the other apple, that lets Shaun and Rebecca see and talk to him. Acting on that, and given that he's had a year to practice, Altair is able to replicate that to the point where he can use the apple as a translator. Making himself visible to other people is a lot more difficult, and he's not at the point where he can do that. Yet. Or maybe not ever! I don't know. Probably it'll happen at some point, when I decide it's dramatically appropriate.
And a quick note that's sort of important but I keep forgetting to mention- I really have no idea what happens to Altair in canon after AC1. I mean, I have a kind of vague knowledge that he leaves Masyaf, marries Maria, has a couple kids, one of them dies- but most of that comes from Revelations and I'm always way too distracted with how cool it is that Ezio's going through Altair's memories to actually pay attention to what's going on. So that's my bad, and because I don't feel like doing research I'm just assuming that time travel messes everything up and so basically Altair's whole life after AC1 in this story falls into AU categories.