[Nate stares at him for a long moment before closing his eyes briefly, almost wincing.]

Don't ask me that when it's a what-if and not something you even know if it ever could be possible. You don't—I can't open that up again.

[He rests a hand on his chest, like he can show the kid where Sam's death ripped a hole in his heart. It took so long for that wound to heal as much as it did. And now imagining what if, what the repercussions could be...it starts to tear it open again.]