Natsu stared in horror as the demon roared its triumph to the skies. The rest of the guild lay scattered around, most members unconscious or otherwise incapacitated.

"No…" Lucy whispered hoarsely from beside Natsu. "We lost…"

Their plan to kill the demon had failed. Everyone was out of magic power, and although the demon had sustained minimal damage, it wasn't enough to stop the beast from its rampage. Soon it would finish off the rest of the guild and destroy what little remained of the city. And after that… Well, he supposed that it would continue on slaughtering innocents and tearing down cities.

A feeling of hopelessness welled up inside Natsu, and he hurriedly tried to quell it. He never gave up. Never. And Fairy Tail shouldn't ever give up either.

"Damn it," Erza muttered from where she lay sprawled across the ground a few feet away.

Natsu ignored her and instead began to slowly push himself off the ground, his body trembling with the strain.

"Natsu?" Lucy asked uncertainly.

He ignored her too, and used the surrounding rubble to help him stand on his feet. He swayed slightly, but his eyes narrowed in determination. He would just have to try squeezing out some magic power from somewhere—he couldn't just lie down and watch everyone die.

"Natsu, it's over," Lucy said quietly, her voice laden with defeat. "There's no way you have enough magic left."

"It's not over," Natsu insisted, leaning heavily against the remnants of a crumbling wall to remain upright. "I'll never give up."

"Natsu's right. It isn't over."

Everyone turned to look over at where Makarov was sitting with his back pressed against a pile of rubble. His eyes were grim as he stared fixedly at a point to the left of the approaching demon.

"Master? What do you mean?" Erza asked. As she saw Natsu rise, she too began struggling to stand.

Natsu bit back his initial questions and instead followed Makarov's gaze, his eyes widening as he saw what the master was looking at.

"Gray!" he called in surprise.

Sure enough, the ice mage was striding purposefully toward the demon, a look of resignation and determination hardening his face. One pale hand lifted into the air and fluttered in acknowledgment, but Gray didn't speak or take his eyes off the demon.

"He's not even hurt!" Lucy said, with a mixture of surprise and relief.

Gray had disappeared at the very beginning of the battle, and they had all been worried about his safety. No one had seen him again until now. Looking closer, Natsu could see that Lucy was right. Gray was not only unharmed, but appeared to still have quite a bit of his magic left. The dragon slayer suddenly felt uneasy. Gray should be in the same shape as the rest of them: injured and out of magic.

"Why does he still have so much magic?" Natsu asked abruptly, narrowing his eyes as Gray's ice lances hit the demon's side so that the beast turned away from the rest of the guild and focused on the ice mage.

"You're right," Erza said with a frown, finally pulling herself to her feet. "After he disappeared I feared the worst, but he doesn't look as if he's been battling at all."

Makarov sighed heavily. "He hasn't."

Everyone turned to stare at him again.

"What? He just left us to fight alone?" Natsu asked angrily, eyes flashing.

An abrupt movement caught his attention, and he swung his head back around to study Gray.

"No," he breathed, eyes widening as the ice mage took on a familiar stance. "Gray!" he yelled. "Don't you dare even think about using iced shell!"

He started forward, his wounds temporarily forgotten in his desperation to stop his friend. Gray glanced over and raised a hand, and Natsu yelped as a towering wall of ice shot up from the ground right in front of him.

"Gray!" Natsu growled in frustration and punched the wall. It didn't budge.

"Natsu, stop," Makarov said tiredly.

"What? You can't expect me to just let him give up and kill himself!" Natsu snarled, striking the icy barrier again.

He jerked back in surprise as another fist hit the wall beside him. Apparently Gray's suicidal intentions had galvanized Erza into action, and even Lucy was staggering to her feet, a look of fear on her face.

Makarov closed his eyes and let out a breath. "This was the backup plan. He agreed to it."

"He agreed to it? You mean, you asked him to do this?" Erza asked, stunned. A look of indignation swept across her features.

Natsu froze. Backup plan?

"Oh my God," he whispered. "This is what he was talking about?"

He distantly heard Lucy asking what he meant, but his whole focus was now on the small figure standing alone against the towering demon. Gray had resumed the all-too-familiar stance, and his power was swirling about him as he gathered up all the magic he needed for his last attack. The demon had paused and was watching him impassively, clearly unaware that this spell would be much more powerful than those it had faced before. Natsu could see it all because the wall of ice was unnaturally clear and undistorted, and it wasn't fair, because if he could so clearly see what was going on then he should be able to stop it.

"I told you that you weren't just a damn backup plan!" Natsu shouted as loudly as he could, the last remnants of his magic swirling up in response to his panic. He attacked the wall again, determined to break through, but even with the flames aiding his punches, the ice didn't so much as crack.

"I told you that you had a place on our team, that you were important too! I told you!" he screamed, slamming into the wall again. Through the ice, he could see Gray's shoulders hunch slightly as his friend heard his words, but his spellcasting didn't waver.

"I'm the backup plan. If we run into something we can't beat, I'm there to ice it over."

"I told you that you were more than a backup plan! You told me that you understood! You looked me in the eye and told me that you understood!"

Natsu was vaguely aware that the others had joined him in attacking the wall, tears streaming down their faces as they heard what he had to say, but his fear and desperation made it impossible to pay them any mind.

"Why didn't you just tell me?"

"I leave you alone to 'just think' and next thing I know you'll be off trying to use that damned iced shell spell again or running off on solo jobs for a month to avoid us."

"How did–? Perceptive."

Oh God, Gray had basically told him exactly what he was going to do, and Natsu hadn't even realized it. His fiery fist slammed into the wall again, but nothing happened. Why wouldn't it break? Had Gray always been this strong?

"Damn it, don't you dare die! I didn't give you permission to die!"

"I'm tired, Natsu."

"I told you not to give up on me! You said you wouldn't give up!"

The wall shuddered with the impact of the blows raining down on it, but didn't so much as crack. Beside him, Natsu could hear Lucy sobbing.

"I told you that we cared! I told you that you belonged! I told you that you were more than just a backup plan!"

He hissed in frustration as his attacks bounced harmlessly off the wall. Erza cursed loudly as she was once again repelled as well.

"I knew I should have made you tell me what happened. I knew something was wrong if you were talking like that. Damn it!"

"Natsu, please." Makarov's voice cracked, and Natsu knew that the master was crying. "I wish it hadn't come to this, but we don't have a choice anymore. Either Gray sacrifices himself or the demon will kill us all and continue on killing innocents once we're dead. Believe me, this wasn't what I wanted, but he's the only one who can stop the demon now."

Natsu paused, gritting his teeth and clenching his fists as he stared fixedly at the ground with narrowed eyes. He let his breath out in a low hiss as Makarov's words told him what he already knew, even if he didn't want to admit to the truth in them.

"You think I don't know that?" he asked softly, his voice wavering slightly before hardening again. "What he said that night… If he had just told me what you asked of him then maybe we could have come up with a different plan, but it's too late for that now. I know that. But…"

He looked up and turned to face Makarov. Everyone else paused as he stared them down with cold eyes.

"We turned him into a backup plan, just like he said. Maybe we didn't want this for him, but we did it anyway. But I don't want him to die thinking that we don't see him as anything more than some stupid backup plan, because he's worth so much more than that to us. If he has to die, I want him to die knowing that we didn't give up on him, that we fought for him to the very end."

A strangled sob escaped Lucy's lips and Erza covered her face with her hand. Makarov bowed his head, tears dripping down his wrinkled cheeks.

"So don't tell me to stop," Natsu continued, pushing back his despair to regain some of his usual passion. "He's not going to die knowing that we just gave up and watched him sacrifice himself. If you want to sit back and watch, then fine. But I'm going to keep fighting, because if he's going to die, he's going to die knowing exactly what he means to us."

"Natsu, you keep talking about a conversation you had with Gray," Erza choked out. "What did he say?"

Natsu thought back to that night on the roof, only a few days before. Perhaps Gray had been seeking comfort and reassurance after being informed of his role as the backup plan, but that wasn't really his style. Under normal circumstances, the ice mage wouldn't have told Natsu anything, or at least would have made up a story to save face. But he hadn't. Why?

Natsu couldn't help but think that it had almost been a gift. Gray was good at hiding his emotions, and although Natsu could sometimes tell he wasn't happy, he'd had no idea that his friend had been thinking such things. Without that conversation, Natsu would never have known how Gray really felt. Gray would have died, and Natsu would have been none the wiser.

"He said a lot of things," Natsu said quietly. "But I think what he was really trying to say was 'goodbye'."

With that, he spun back around and slammed his fiery fist into the wall, crying out in frustration. He felt something wet on his face and realized that he had finally started to cry.

Beside him, Erza and Lucy attacked the wall with renewed determination, tears streaming down their faces.

"Gray, you're one of the strongest mages I've ever known!" Lucy called, her voice choked with tears. She beat helplessly against the wall, not having the strength to summon another spirit. "You made me feel welcome in the guild when I first joined. You made me smile and laugh, and I can never thank you enough for what you did for me."

Natsu glanced over at her in surprise, before nodding sharply. After all, he wasn't the only one who had something to say to Gray.

"Remember when you found me crying by the river, back when we were children?" Erza asked, slamming into the wall futilely, her battle against the ice just as futile as her battle against her tears. "When you told me that I shouldn't have to cry alone and you sat by me until I was out of tears? You'll never know how much comfort you brought me that day and for years afterward, but if I could give even a fraction of that back to you...I'll tell you what you told me then: you aren't alone!"

Natsu was distracted as Makarov suddenly struggled to his feet to join the offense, using the last of his magic to make his own contribution to the attack on the invincible barrier.

"You're one of the best and brightest young mages I've seen in a long time. I wish that I didn't have to ask such a thing of you, but know that you will always be one of my children. You will always belong to Fairy Tail!"

"Gray!" Natsu looked up in surprise as Happy appeared overhead and hurtled into the wall in a blue blur. He had thought the Exceed was down for the count, but apparently he had woken up. "Gray, you're better than fish!"

That made Natsu half smile through his tears, although the simplicity and strength of the compliment also made him choke up again.

"I told you, you've always belonged with us!" he called. "And even with all the fighting and the name-calling, you've always been my best friend. Do you hear me? Please–" His voice broke, and he had to struggle past the lump in his throat. "Please tell me that my voice reached you!"

With a cry, he threw all his remaining strength into one last punch. There was a loud snap as jagged cracks suddenly appeared in the ice, splitting through the wall where Natsu's fist had landed and then spreading outwards. The dragon slayer stared. He had done it? He had finally broken the wall? With a low rumbling sound, the entire wall collapsed, leaving only a pile of broken shards of ice in its place.

Natsu felt a surge of hope as he tore his gaze away from the crumbling wall to look at Gray again. Just as quickly, he felt his heart sink as he heard the words he had been dreading this whole time.

"Iced shell!" Gray yelled.

Natsu started running forward, even though he knew it was too late. He realized bitterly that he hadn't broken through the wall at all—Gray had stopped maintaining it because he knew he was finished casting his spell.

"Gray!" he cried.

The demon bellowed in confusion and outrage as ice began spreading over its body, but Natsu only had eyes for his best friend.

Gray finally turned to face them. He was wearing a sad half-smile, and a single tear rolled down his cheek. There was a sharp snapping sound and a series of thin cracks suddenly spiderwebbed the right side of his face, leaving his right eye to shine a clear, icy blue instead of its normal dark color. Natsu grimaced as he realized that it had begun—Gray was turning into ice right before their eyes.

"Gray," he whispered, staggering slightly.

The ice mage focused on Natsu and his eyes softened a little. He suddenly thrust his right hand into the air and bent down all of his fingers except his thumb and index finger, making the Fairy Tail sign as his last gesture.

Natsu's breath hitched as he thought about the meaning of that sign: "Even if I can't see you...no matter how far away you may be...I will always be watching you."

And that was all it took to undo Natsu Dragneel completely. His silent tears turned into loud sobs. Even as he scrubbed at his eyes with his left hand, he raised his right in the same gesture. Behind him, every member of Fairy Tail that was still conscious staggered to their feet and copied the sign.

Gray smiled then, and although it was still tinged with sadness, it was also laced with pride and acceptance.

And then, just as the ice fully encased the demon, there was a shattering and Gray was gone.

"No!" Natsu cried, falling to his knees. He stared in horror at the place his friend had just been standing, tears still flowing down his face. "No," he repeated again in a whisper.

As the last echoes of Gray's power reverberated through the air, a soft breeze suddenly sprang up and wound its way around the assembled guild members. It was gone again almost as suddenly as it had appeared, but before it vanished, it carried the faintest echo of a voice that whispered in their ears.

I'm so sorry, but thank you for everything. I have always heard your voice.

Goodbye.

UPDATE: I really like how wonderfully tragic this piece is when it stands alone so I didn't originally intend to write anything else for it, but here we are. I'm calling the other stories "companion pieces" because I don't really see them as "prequels" or "sequels", even though, chronologically speaking, they kind of are. This story can stand alone perfectly fine, even if the others can't.

"Saying Goodbye": A series of 5 related one-shots (one each for Lucy, Erza, Juvia, Cana, and Makarov) plus a "prologue" and an "epilogue". Each of the body one-shots will focus on how Gray secretly says goodbye to the titular character, in the same way that he said a goodbye of sorts to Natsu in the first part of "The Backup Plan". Chronologically speaking, it takes place in between the first and second parts of "The Backup Plan", but it should be read second of the three stories.

"To Those Left Behind": A series of 7 related one-shots (one each for Lyon, Lucy, Erza, Juvia, Cana, Makarov, and Natsu) plus a "prologue" and an "epilogue". Each of the body one-shots will have two parts: one focusing on how Natsu comforts the titular character and the other focusing on how Natsu is coping with his own grief. This story will be more Natsu-centric, but the structure will parallel "Saying Goodbye" in many ways. Chronologically speaking, it takes place after the events of "The Backup Plan", and it should be read third of the three stories.