Charles won't look at him. He hadn't expected it, but Erik's heart clenches in response. He's wearing the helmet, but there's no doubt that Charles knows he's there. The truth of that is in the resolute set of the jaw, the tilt of his head, and the way he curls his hands into fists on the arms of his chair.
"Do you know what it does?"
He's unprepared for the question and it takes a moment's thinking to work out what Charles means. "Yes."
Erik knows he's answered too quickly even before Charles huffs a laugh, quiet and bitter, and looks at him. When Charles looks at him, eyes tired and pained, he thinks coming here is a worse mistake than that day on the beach.
"No, Erik," he says, quietly. "You don't."
Within the safety of the helmet, he tries to picture it. Charles tried to show him, once, what it was like for him, the world and the sound of the hearts and minds within it. He'd shown him, in a roundabout way, what it was to see him in that fashion and, now, with that fresh in his memory, he imagines its sudden absence.
"It was as though you died," Charles smiles, weary and sad. "Then I did."
This time, it's Erik who turns his head. He's apologized a thousand times since then, behind the helmet where Charles cannot hear, but the words stick in his throat. He doesn't regret his choice, it wasn't a choice at all, but this, losing Charles, he regrets. Hates.
He sighs, heavy, and closes his eyes as he removes the helmet.
The response from Charles is immediate; a soft groan of relief. Something murmured which might be 'thank God' but Erik's too far away to hear. He sets it aside even as Charles says, quietly, "You underestimate yourself, you know. Reading you is never quite so easy as you might think."
He stands, silent, but flinches within himself. It isn't like Charles to make such a jab, not the Charles he knew, but whether it is or not, Erik feels the guilt of it just the same. "There wasn't any other choice, Charles."
"Not from where you stood, perhaps not," Charles sighs. He looks toward the window. There are children playing on the grass below, faces Erik doesn't know mixed with faces now changed forever, and the longing catches him off guard. "We're not them, Erik. Why choose their methods?"
"You know why," he says, the words like ash on his tongue. He takes a step closer, burning with the urge to make Charles see. Make him understand. This isn't enough. It will neverbe enough.
"It is for now," Charles says, looking at him again. "We are different, Erik, but not in the way you think. We have a chance to be better than them and—don't. Don't try to tell me we already are." His hands thump the arms of his chair and the meaning is clear enough.
Erik has spent months hating Moira for that. Day in and day out. Looking Charles in the eye, however, he finds the hate landing on its true target and he can't face it.
No, my friend, Charles's voice is gentle in his head, loving, more than he has any right to ask for, but to hear it nearly sends him to his knees. We've spent enough time hating.
"Charles."
"Yes, I did hate you. I hated you for betraying my dreams, for putting me in this chair, for taking Raven—I even hated you for leaving me, even though I'd never said a word of what I felt." Charles moves the chair toward Erik, Hank's handiwork visible in the easy way it negotiates the study, the metal of it—or, perhaps, Charles himself—whispering a siren's song against Erik's skin. "For putting that goddamn helmet on and shutting me out most of all."
He can hear Charles perfectly now, no matter how much he wishes he couldn't.
You can't kill billions, Erik. I won't allow that.
"I don't want to kill billions, Charles." Erik sinks to his knees, looking him in the eye. We're not safe, not like this, something must be done.
"And something will be," Charles promises, "I won't let them hurt us." You. "I'll never allow that, but I will not murder them to do it." He leans forwards in the chair, fingertips brushing Erik's cheeks. You will always be welcome here—you will always be safe here—with me. "And I won't allow you to do it either."
Erik thinks of Shaw dying, Charles's voice screaming in time with him, and watches Charles close his eyes against that memory. Leaning forward, he brushes a kiss across one and then the other before pressing his lips to Charles's.
And you with me.