The song I listened to that inspired this piece was 'Morning After' by Maureen McGovern.
The spell had hit him before he could react, and he crumpled to the ground slowly, falling to his knees first, and then backwards as his spirit escaped the prison within which it had been trapped for so long. His wife looked at him, tears in her eyes, which leaked out as she heard the last word that escaped him.
"...Padfoot..."
With that, Remus John Lupin crossed to whatever lay on the other side. When he stirred, he saw how bright everything was...he blinked, allowing his eyes to adjust to the light, and saw a hand extended to him.
"Took you long enough, Moony." The voice was familiar...Remus took the hand, and traced it back to a familiar face...one he hadn't seen in several months.
"Sirius..." Remus breathed, standing up and looking at him. "You look...good." Remus blushed lightly, and pulled him into a tight embrace. "I've missed you." He murmured, burying his face in Sirius' hair.
"I've missed you too...Remus..." Sirius clung to him tightly. "Come on...it's time we got going."
"Where are we going?" Remus smiled, gently stroking the side of Sirius' face.
"Where do you think?" Sirius laughed, shaking his head. "James is waiting, and Lily too. I came to meet you...because I missed being without you...and I didn't want you to have to travel there alone." He slipped his hand into Remus', and squeezed it gently. "I love you, Remus..."
Remus thought briefly of Nymphadora, and a brief pang of guilt crossed his face, which Sirius saw.
"I got married, after you died..." Remus whispered, kissing the back of Sirius' hand. "I didn't even love her...I think I was just trying to bandage my broken heart..."
"I know..." Sirius smiled softly. "I still love you..."
"I love you too, Sirius." Remus looked into his beloved's grey eyes, which held all of the love in the world. "Let's go."
The two walked to the train that waited for them, and left, going into eternity together.