It was after the battle in Stella when it happened. Natsu collapsed into Lucy's arms, only he wasn't getting back up. Lucy shook his shoulders in growing fear and agitation, the tears burning behind her eyes but refusing to fall.
"Natsu, Natsu!" She was nearly shouting his name now, and he still wouldn't open his eyes. His breathing was ragged and uneven, sweat stood out on his brow, and he was completely still in the celestial mage's arms. She rested her forehead against his, exhaustion from the battle finally catching up to her.
"Please wake up," she mumbled in his ear, desperate and pleading. A choked sob escaped her, and the burning tears finally trailed down her cheeks. "Please, please, Natsu..."
She didn't know why she started singing. She had a half-formed memory of her mother singing to her when she was ill, and it washed over her like a wave. Her voice was cracked with dehydration, dust, and tears, but still, she sang.
"You are my sunshine, my only sunshine. You make me happy when skies are gray..." she had to stop, unable to keep going through the tears. She muffled her sobs against his scarf, clutching onto what remained of his clothes in terrified desperation.
Lucy jumped when another voice, just as dry and cracked as hers, picked up where she had left off. It came from the boy she held in her arms, the one she loved so much.
"You'll never know, dear, how much I love you. Please don't take my sunshine away."
Natsu's right hand, shaking terribly, reached up. He touched her cheek, and a weak grin found its way onto his face. "I love ya, Luce. Just wanted ta tell ya, before..." he trailed off.
Lucy's tears were dual rivers now, and her voice shook with the amount of emotion her heart contained. "You'll b-be okay-ay, a-alright? D-don't talk l-like that-at!"
"Oh, Luce..." he interrupted himself as a coughing fit seized him. It racked his body, rendering the dragon slayer weaker and weaker. Natsu's body shook in Lucy's arms, and another sob escaped her. In his hand, running down his chin, in his teeth, was red blood, brighter than Erza's hair.
"Y-you'll g-get-et b-bett-etter," she told him, forcing as much confidence into her voice as she could muster. There wasn't much, as her voice still shook like a leaf.
He smiled that beautiful smile up at her again, though this time, he took care to hide his teeth. But it was a tired, fading smile.
"You are my sunshine, my only sunshine," he sang again, softer this time. His eyes were fighting closure, even as his body shut down. Lucy could feel his heart going at a thousand miles per hour in his chest, going so fast she feared it might burst.
"Are-aren't you g-going to-o sing me the r-re-est?" she sniffled, wanting him to stay awake. His eyes were closed, but the smile remained. He was fading, fast.
Slowly, the hazel-green eyes of her dragon slayer flickered open again to look at her lovingly. He sang the next line, though the words were heavily slurred.
"You make me happy when skies are gray..." his eyes slipped close again, but this time, they didn't open again. Lucy felt his heart come to a stop, and she almost screamed. She laid her head against his heart, desperately hoping she was wrong.
I can't hear his heart.
The thought pounded in her mind.
I can't hear his heart.
Natsu's really... gone? But that's not right, he was just there, singing to her, to try and keep her calm. The fear and sadness overwhelmed her, but she was out of tears. Her eyes could shed no more, so she just dry-sobbed over him, willing him to wake up and snap out of it. Eventually, she couldn't do that anymore either.
His last words echoed in her mind. He'd never finished the song.
Lucy sat up, sniffling and struggling to breathe as she whispered the last line of the song to him in the twilight.
"You'll never know, dear, how much I love you. Please don't take my sunshine away..."
This time, her voice didn't break.