Foggy walks away dizzy and barely able to see where he's going through everything whirling through his brain. He hears Matt sniffle as he closes the door behind him. He can still hear it from the hall.
Matt's crying, he just made Matt cry, Matt's crying and he almost died and now he's crying and Matt's not supposed to cry and Foggy's too twisted up to know if he feels guilty about making Matt cry but he sure as hell knows that Matt's not supposed to cry even if he deserves it. Foggy's about to cry, too. He can't. He can hear Matt crying and that means Matt's freaky superhearing can sure as hell hear him too, or smell his tears, or something, and he doesn't want Matt to know he's crying and he's not even sure why.
He holds it down, holds it in his throat as a painful burning lump that feels like plasma, bright star burning in his throat, but he holds it down. He gets down to the street. Matt can still probably hear him down here. Maybe even can hear his heartbeat, still, hear how desperately his heart is pounding, but there's nothing he can do about that, so he starts down the street, away from Matty, from his ears and his knowing because somewhere there has to be privacy, if he can get far enough away he can keep Matt from knowing how much he hurts.
He holds the ball of plasma down as he walks down the street, still dizzy, but his eyes don't even water a little, just aim straight ahead, probably staring as blank and unfocused as Matt's, and now he wonders if that's a lie too, does Matt just look like that to keep people from finding out who he is, what he can do? He's lucky his home's close enough to walk, he doesn't have to take a cab, because he wouldn't have been able to talk through that ball of fire, if he opened his mouth either there'd be no sound at all or the heat of the burning sun would come out in a scream.
He's at his building, climbs up the stairs holding to the handrail so he doesn't fall, did Matt actually need to hold the rail? Did Matt actually need to hold him, hold his arm, all this time, he couldn't have, if he can do all those crazy things, why did he? And he gets up to his door, stares at it, can't seem to remember how to open it for a minute, just stares at the handle. Slowly he gets enough awareness to pull the key from his pocket and get it in the lock, on the second try, as clumsy as if he were still drunk, pulls the door open, steps in, closes it behind him, sinks down to the ground, and sobs.
Note: a degenerate star is what remains after the collapse of a small main-sequence star.