After hours of discussion, negotiation, compromise, they're alone together in Charles' study. As always, Charles is in his chair; as always, Erik still has the helmet on (despite the near-hysterics Alex and Hank and Sean went into when Charles said he would allow it).
Sometimes, Charles wonders if Erik were a figment of his imagination to begin with. But that's wrong, he knows it's wrong when he can so clearly remember what it felt like, Erik's presence against his mind. It's too clear to be something he dreamed up on his own, and he knows he's not mad.
Other times, Charles wonders if Erik died on that beach, if he's been gone from the moment he placed the helmet on his head. For all that no one else seems to have any trouble reconciling Erik and not-Erik, Erik and Magneto, Charles has always had difficulty taking Erik's shade seriously. He's not real, any more than a character in a movie or television show is real. Only people with minds get to be real.
(He's aware the flaw may be with his own perception, if not-Erik seems real to everyone else. Acknowledging it as a possibility is one thing, believing it to be so quite another.)
"Well?" not-Erik says. If Erik had said it, in that tone and with that twist of his mouth, it would probably have been due to...impatience, irritation. Fear as well, perhaps; Erik had been ruled by fear, for all he'd reached out for anger, gripping it hard with both hands no matter what else might beckon.
"...Ye-es?" Charles says after a moment, and a little absently. It's hard to pay attention, hard to make himself care. Conversing with not-Erik is like talking to a rock, except rocks don't talk back.
"Charles—"
Not-Erik takes half a step forward, halts. He makes a noise, a low, almost strangled sound at the back of his throat, then reaches up and tears the helmet off his head. Maybe he drops it to the floor. Maybe he flings it away from him. Maybe it lands, rolls away, comes to a stop somewhere.
Whatever happens to it, Charles doesn't notice, but it's not in Erik's hands a moment later, when he finishes crossing the room, drops to his knees, takes Charles' hands in his own and buries his head in Charles' lap.
"Erik," Charles says, scarcely believing it—but it's impossible to argue with the evidence of his senses, Erik shoving guilt and grief and love and hope at him, so much that he could drown in it. "There you are."
Then there's joy, and it's all Charles' own, surging up through him, unexpected and unasked for and so, so welcome.
Charles pulls one of his hands free of Erik's, rests it on the back of Erik's head. His hair is oily, stuck into an odd shape.
"You have the most awful case of hat hair," Charles says, and if he sounds absent now, it's only because he's never been so overwhelmed, not even the first time he ever felt Erik's mind. He remembers the taste of salt on his lips then, and more than remembers; there's salt on his lips now, though he doesn't remember when either of them started crying. "It's decidedly unattractive, I'll have you know."
There's something else, too, along with the joy, something Charles could never quite let himself feel while Erik was gone, or any of the times not-Erik has come to him over the past few years. They're going to have one hell of a fight before the day is out; they're going to fight about everything Charles has always declined to engage with not-Erik about over the past few years.
Charles finds he's rather looking forward to it.