Edit 07/01/14: This WAS my first Sonic fanfic, and it received a lot of positive feedback since I posted it months ago. Initially a oneshot with potential, but due to popular demand and promises I refuse to break, this story is being made a MULTI-FIC. Haha.

Chapter summary: There were a lot of things that Shadow didn't understand about Sonic, why he did what he did. But when Sonic pays the ultimate price for another's sake, all the questions he leaves behind consumes Shadow from within. Only his friends can answer them, and Shadow must come to a life-changing revelation for him to accept the peaceful life Sonic left for him.

Warnings: Slight OOC on Shadow's part and possibly the other characters, depending on how you view them, a little character study for Sonic, which may differ from others. Lastly, this prologue has a very, VERY different writing style from the rest of the fic, which I hopefully will be able to finish.

Disclaimer: Sonic the Hedgehog and all other characters all belong to SEGA…I think…or whoever the heck owns them. First story, people, how the heck could I own the friggin' franchise?!

Enjoy. Hope it doesn't suck too bad.

PROLOGUE: THE BEGINNING

"You always have to have the last word, don't you, Faker?"

Shadow glared at the hedgehog sitting lazily in front of him with crossed legs, wide, alert eyes and a smiling face. They were on a cliff a few kilometers from Station Square and Green Hill, where Sonic and his friends lived. The scene before him was the sparkling sea, dark and mysterious under the early evening sky. The first few stars glimmered above, and in a few minutes he knew a full moon would appear as well.

But the only thing that mattered was the figure in front of him – a statue of Sonic the Hedgehog, carved in a special kind of stone that would not easily weaken or be destroyed. The way the statue smiled and had eyes that follow him infuriated Shadow to no end, much like the real Sonic.

Shadow kept staring at the statue, willing his anger to manifest in his eyes. Never in his life had he been as angry as he was. It was at par if not beyond the fury he felt upon learning of Maria's death. In fact, he was itching to remove his inhibitor rings just to unleash his rage, but restrained himself.

"You probably think you've finally won, don't you? That this is just another race between you and your archrival." Shadow seethed. "I'm even more competition for you than Eggman, aren't I? So why shouldn't you be laughing at me right now?"

Ever since they had met, Shadow and Sonic had always been at odds with each other. They were so similar in appearance and abilities, and yet so opposite in personality. Sonic was a cocky and carefree daredevil while Shadow was a cold and serious loner. They clashed every time they met and the number of times they were on opposite sides of the battlefield were too many for Shadow to remember.

Again, Shadow found the urge to vent his frustrations out on a listener who could not talk back. Either because he did not want someone to really understand what he was saying or because he did not want to listen to someone failing to, he was not sure. All he knew was that he had to let it out before it consumed him from within.

"I'm your archrival, Faker. So why did you come for me in the first place?" he spat.

Come and rescue Shadow, that is, from a fate worse than death, and even dragged along all his friends with him. That was just a week ago. Shadow could still remember how he was strapped to a table, already too exhausted from the searing pain all over his body, a side effect of the antigen GUN had used him as a guinea pig for.

Sonic had demanded the commander – not the one who accepted Shadow as an agent, he had 'mysteriously died in his sleep' – release Shadow and end his project of creating a new weapon out of the hedgehog. The commander, his predecessor's hasty replacement, had refused and launched an attack on them.

The thought of the speed demon sent a pang of pain through Shadow's chest but for what reason, he was not sure. Ever since the change in command of GUN and his demotion from agent to lab rat, there was a lot of things he wasn't sure of any more.

Like why Sonic suddenly had the urge to become a noble idiot. And for Shadow, of all people!

"I never asked for your help, Faker." He continued in an accusing voice. "It was none of your business. Why couldn't you just leave me to it? It was my burden and mine alone."

Back in the lab, Sonic had managed to run to Shadow, release him from his bindings and passed him on to Knuckles and Rouge, ordering them to retreat and get to safety. He also told Tails and Amy to join them, as they would probably be attacked by even more agents on the way out. Sonic said that he would remain in the lab to stall the commander and most of the GUN army.

Then, Shadow had wanted to fight too, but he could barely even stand on his own. Knuckles and Rouge had to put one of his arms around each of their shoulders to support him. Sonic, with a cocky smile on his face, had reassured them that he would be fine.

Returning to the present, Shadow pounded the ground in anger and frustration, not enjoying having to remember everything in detail. Why did Sonic have to be so arrogant?

"Did you think that you could handle it, blue hedgehog? You aren't invincible, there was no way you could. For all that you've survived, you're still just a hedgehog!" Shadow hissed at the statue in front of him. "You aren't the ultimate lifeform. I am!"

A chaos spear materialized into Shadow's palm and he threw it in rage, but subconsciously aimed to miss the statue. It flew down beyond the cliff and out of sight. He felt pang of guilt and he almost took a step back from the blow. It had hit him so hard that he could already feel his chest constricting from the pain, as if it had manifested physically.

In his mind, he saw the moment that changed everything. Just as Knuckles and Rouge dragged him out the laboratory's door, the commander had smashed a small but deadly bomb, causing it to set off. Shadow had willed enough energy to yell Sonic's name, telling him to escape even though he knew that the bomb's radius would reach him and his friends, even if they could run.

To his horror, Sonic didn't rush out of the lab. Instead, he had run to the computer on the opposite side of the laboratory and pressed a glowing red button. In that split second, Shadow had caught Sonic's gaze before the metallic door slammed down, effectively muffling the explosion that happened a second later.

Sonic, along with the commander and a dozen GUN agents were trapped inside. Shadow knew there was no way he could have survived an explosion that close in a confined room. It was complete suicide.

What made the pain in his chest worse was that he knew that Sonic knew the same but didn't stop. It was no accident or panicked mistake on the hedgehog's part. He saw it when their eyes connected. He was fully aware of what he was doing and did it anyway. Sonic had died willingly for him. He had made the ultimate sacrifice so Shadow could be where he was that day.

"Why did you do it, Faker?!" Shadow had stood up as he yelled, staring down at the still smiling statue with angry eyes that held a faint glimmer of hurt in them. "I never asked for you to save me! I'm your opposite, your greatest rival. So why the hell would you just throw your life away for mine, Sonic? Tell me!"

Shadow felt some kind of moisture behind his eyes but blinked them away. There were so many unanswered questions and the only person he could ask was dead, so Shadow was reduced to speaking to a stone replica of the original being. He had become desperate, and if this continued, he'd probably go insane too.

He didn't know why, but he felt sorrow, confusion and hurt stirring within him. An unfamiliar pain in his chest squeezed at his heart and Shadow dropped to the ground with clenched fists, trying to regain some sense of dignity, the numerous questions of 'why?' still revolving in his head.

"Because you weren't just Sonic's rival." A voice said from behind. "You still aren't."

Suddenly aware that he was not alone, Shadow looked over his shoulder to see the red echidna standing behind him a few feet away with his arms crossed and the same hard expression he always wore on his face, but with exhaustion and grief mixed into it. The past week had not been especially kind to him either.

"How did you find me?" Shadow asked, but his voice lost its cutting edge and coldness. Instead, it was void and empty of emotion, as if Shadow had nothing to live for anymore.

Knuckles must've been in a good mood, for he dropped his giant hands to his side and his face broke into a soft smile. "We've been looking everywhere for you since you left the hospital last week. I should've known you'd be at his memorial."

Shadow turned away to stare at the sitting statue that was Sonic's memorial. The only reason they could not call it a grave was because they never recovered the body, having had to flee quickly. It didn't matter, anyway. They all knew that Sonic was dead and gone.

Shadow made no point to talk, hoping that the echidna would get the hint and leave him alone. He was almost disappointed when Knuckles finally spoke up.

"Tails, Amy, Rouge and I decided to have a picnic dinner then camp out for the night. We're hoping you'd join us."

"I wish to be left alone, echidna." Shadow replied in a flat voice, again hoping that he'd get the message.

"Aw, come on." Knuckles said in a tone that eerily resembled Sonic's whenever he would ask to race. "You're voice lacks its usual conviction. Don't you ever get tired of being alone?"

"You're one to talk, spending your entire life up on that island." Shadow responded a bit too bitterly than he would have liked. But he did have a point.

"Yes, and now I'm spending time down here." Knuckles replied easily. "It's what Sonic would've wanted. Don't you think so too, Shadow?"

His words triggered memories in Shadow's mind of the mentioned blue hedgehog pestering him with invitations to adventures, lunches, hang outs and the like. All those times he had turned Sonic down and the younger hedgehog would complain to no end. Now a part of him regretted not going to at least one. Now it was too late.

For some reason, Shadow stood up, dusted himself off and gestured to Knuckles to lead the way. He was not sure what made him want to go, but the thought of Sonic made him do so. Together they walked side by side in silence. Shadow was not interested in engaging in a conversation, one because he was too deep in thought and two because it was his fault Sonic had died and he didn't know why Knuckles was not angry at him for it.

Just as when the picnic area came into view, Shadow remembered what Knuckles had first said.

"What did you mean?" he decided to ask, turning his head to look at him.

"Huh?" Knuckles replied in confusion.

"You said that I wasn't just Faker's rival. What did you mean?" Shadow repeated.

Knuckles remained silent for a while then returned Shadow's gaze with sad eyes. "You seem to think that all Sonic saw in you was competition. I used to think that that was what I was to him too, when we first met. But, like he did for me, Sonic always thought of you as a friend."

"A friend?" Shadow said, raising his head in confusion. "We have been rivals since we met until the day he…he left…" he paused to swallow hard "…and we have fought on opposite sides countless times. What leads you to believe he considers me a friend?"

"He died for you, didn't he?" Knuckles said in a tone not accusing, but still managed to stop Shadow from walking. "He wouldn't do that for just anybody."

They were only a few meters from the others by then, and Knuckles had gone ahead to make their presence known. Amy, Tails and even Rouge greeted him warmly and, upon catching sight of Shadow, waved at him and gestured for him to join them.

The four friends were surrounded by different kinds of food, from fruits, to cake, to sandwiches, and even chilidogs. A single lamp rested in the middle, casting a strong enough glow for them to see, but not outshining the light from the moon and stars. In spite of the warmth and coziness they offered, Shadow could not find it in himself to sit down with them. He stayed outside their circle, head bowed and eyes downcast.

"Come on, Shadow!" Amy said cheerfully, clearing away a space on the checkered cloth for Shadow to sit. "Feel free to eat whatever you like."

"Yeah, Shadow." Tails said through a mouthful. "It's really good."

"Even the ultimate lifeform should eat something once in a while, you know." Rouge said lightly.

"How?" Shadow whispered loud enough for them to hear, earning him four questioning glances. "How can you be so accepting of the cause of his death? He was your friend, was he not?"

It was true. Anyone could see that Sonic had a place in their heart. In fact, he was the glue that held them all together. He was Tails' brother, Amy's idol, Knuckles' best friend and Rouge's ally. He was a part of their lives, a part that was now lost forever, and they could just accept the reason Sonic died amongst them? Wouldn't that be dishonoring his memory?

Shadow managed to look up and was surprised to see their faces. Instead of anger or confusion or even pity, they held some kind of sad understanding and kindness, as if they knew some kind of truth he didn't but was going to find out.

"You see, Shadow…" Tails began in a gentle and sad voice. "We never really talked about it, but there was always an unspoken understanding among us about Sonic. Deep down, we always knew he would get himself killed for one of us."

Shadow took a step back. "You knew?"

"It's pretty obvious, actually." Rouge answered. "The quickest way to get to Sonic was through someone he cares about. He would rush into battle without a plan, or get himself into something he can't get out of if it meant saving us."

"Like when Sonic learned that GUN was after you." Amy added. "Sonic had wanted to locate and burst into their base and find out why, or run around the world to make sure you were alright. After learning that GUN had finally caught you, he had rushed out in search of the base you were in. It's his greatest weakness, even more so than water."

"His greatest weakness?" Shadow repeated, still not completely understanding it all.

"Sonic cares for his friends so much that, when they're in danger, he forgets everything else." Knuckles explained. "He'll do anything to save them, even disregarding his own wellbeing. We all know he can be impatient, and that leads to his rash actions which usually causes his downfall. It's a trait of his that can easily be exploited."

"Why did you not stop him, then?" Shadow questioned, though he was careful not to sound accusing, only curious. "If you knew that it made him vulnerable, why did you not try to warn him before?"

A moment of silence passed, and the four seated figures exchanged knowing glances.

"Because," Tails answered, his eyes faraway, staring at the past "it's also his greatest strength. I still don't know how he does it, but I've seen him do the impossible if one of our lives were at stake. His speed is his power, but I know that what fuels it is his drive and motivation to save the those that matter to him a lot."

"But why?" Shadow still asked, not fully understanding. "Why would he care so much as to just throw his own life away for someone else's?"

"Because that's who he is." Amy said softly, and Shadow could see that her eyes were shining. "He puts their lives above his own. He never showed it, but Sonic's world revolves around those he cares about and his will for them to be safe and happy."

"Sonic would die if it meant saving his friends." Tails said sadly, his own cheeks now wet. But he looked up at Shadow with shining eyes. "He would have died for us, just as he died for you, Shadow, because that's what we are to him."

For the first time since Sonic's death, the tears that he didn't know existed poured down Shadow's face. He fell to his knees with a thud and covered his face with his hands while shaking with silent sobs. Finally, he understood.

For all his cockiness and attitude, Sonic had a heart that beat for his friends. He lived for them because they are what mattered most. Sonic loved them so much that he would be willing to die for them in a heartbeat. And he, Shadow the Hedgehog, the Ultimate Lifeform, the cold and aloof loner, was Sonic's friend. Sonic cared for him just as much as he did the others.

But Shadow was crying for a whole different but equally important revelation: Just as much as he was Sonic's friend, Sonic was his friend, too. The blue hedgehog had always been there for him, even though he never saw it. He cared for Sonic like a comrade, like a brother. And, just like Tails, Amy, Knuckles and Rouge, a part of him had died too when the explosion claimed Sonic's life.

He was never used to it, but for once Shadow allowed himself to freely show the emotions he had always bottled up. His shoulders shook with silent sobs and his hands kept wiping at the tears that did not stop falling. A part of him felt that he looked undignified and pathetic, but appearances didn't matter to him. Not anymore.

Shadow felt a hand on his shoulder and looked to see Rouge smiling at him, her own eyes wet. Looking around, he saw that Amy, Knuckles and Tails were crying silent tears too, no doubt at the memory of their friend and hero.

"It's alright to cry, Shadow." Rouge said. "We miss him too, and we'll never forget him. But, knowing Sonic, he would want us to live our lives to the fullest, and we can't let his sacrifice go in vain."

Here were people who understood and shared his pain, so he finally gave in and sat on the picnic cloth to join them in their simple meal under the stars. He did not talk as much as the rest, but he was content to simply be in their company. They talked of all the times they had with Sonic, from funny, to scary, to simply stupid, as if he had never really left. Together, they laughed and cried at his memory. It was what Sonic would have wanted.

"To Sonic." Tails said, raising a glass of orange juice in the air for a toast. "You made the ultimate sacrifice by dying for us, bro, and we'll never forget it. We're going to live our lives for your sake. That's a promise!"

Everyone raised their glasses in agreement, even Shadow. Comforted by Tails' words, he smiled for the first time since he could remember. If there was one thing he and Sonic shared, it was that they never went back on their word. He would keep his promise and make the most out of everything, starting then by making friends with those he could truly trust. For Sonic.

"Take care of yourselves, everyone. Catch you on the flip side!"

Shadow whipped his head to the side and gazed at the dark horizon. Only a forest of tall and dark pine trees in the distance stared back at him, through which the wind blew through. He was sure that the voice was Sonic's, but there was no way that it could be him, could it?

"Shadow?" Knuckles called out, confused. "You okay?"

Shadow stared in anticipation of something before turning back with a smirk, relaxing. "I'm fine. Just thought I heard something."

It would be just like Sonic to play tricks on him, even as a ghost, he thought. Shadow looked up to see the star-scattered sky and marveled at their glowing light. However, he chose to ignore the scene above and closed his eyes. He pictured a blue hedgehog with a confident smirk and an outstretched hand calling him 'Shadz' even though he knew he hated nicknames.

'Wherever you are, Sonic,' Shadow told him 'I hope you're happy. Watch out for us, will you?'

Even if it was just in his head, Shadow had a feeling that Sonic heard him.

Sonic crouched hidden among the branches of a tall pine tree, glad that it was dark enough for him to camouflage his blue fur. From his vantage point, he could see Knuckles approach Shadow, who was in front of his stone memorial.

"That's a relief." Sonic murmured to himself, looking at the statue of himself. "I was worried they wouldn't get it right."

Sonic watched Knuckles and Shadow leave and changed vantage points to watch them at the picnic. He was too far away to hear their voices, but his keen eyesight saw how all of them were crying, even Shadow who had collapsed into sobs. Sonic was tempted to go to them, to tell them that he was alive, but he knew he couldn't. Not without putting them in danger.

But after Shadow finally joined them, he saw that they seemed better and happier, either crying or laughing or doing both at the same time. They even gave a toast! There was still a sense of grief and sadness among them, but he knew that they would be alright. They had to be.

"Take care of yourselves, everyone." he said as tears started to fall at the thought of having to leave them, perhaps forever. "Catch you on the flip side!"

With that, Sonic took off, but not without seeing Shadow turn his head and almost see him. But the blue hedgehog had only increased speed under the grueling training he was in, and he easily entered the sound barrier without making the booming noise.

Sonic sped through mountain ranges and valleys until finally he had reached his destination: a secluded cave in the middle of nowhere. However, he did not stop, instead running through the covered entrance. Inside, Sonic ran through the labyrinth of tunnels until he had reached a metal door. Entering, he was greeted by a click of a stopwatch.

"Thirty seconds." The GUN commander said, checking the stopwatch. "That's longer than the time you were supposed to achieve after a week of continuous testing."

"Guess your antigen isn't as good as you think." Sonic replied with as much attitude he could put into his tone. "Told you this whole project was a waste."

The commander's eyes flashed dangerously. "Don't push your luck, hedgehog. We had a deal, remember?" His face broke out into a sadistic grin "In exchange for your friends' safety and ignorance – "

" – I would stay in Shadow's place as your guinea pig without resisting or trying to escape." Sonic recited in a bored tone. "Yeah, yeah, yeah. You're like an old woman who wouldn't stop nagging, you know that?"

"Just making sure you remember your end of the deal." The commander said lightly, gesturing for Sonic to come closer as he inserted a fluid in the injector. Sonic neared, but did not hold out his arm like he was supposed to.

"And let me remind you of your end." Sonic said darkly, his green eyes menacing despite having lost their usual sparkle from taking regular dosages of the antigen. "If I so much as hear GUN having anything to do with any of my friends, any one of them, I will bust myself out and I will let the entire nation know of all the dirty secrets this organization has been hiding behind the cover of protecting its people. Do I make myself clear?"

The commander glared at Sonic, who matched it with his own before answering. "Crystal clear, hedgehog."

Sonic held out his arm which the commander grabbed roughly and stabbed the needle into the crook of his elbow. Sonic instantly felt the searing pain that accompanied the fluid flowing through his bloodstream and winced.

The commander, satisfied, turned away and looked at his watch, counting down the seconds since injecting Sonic.

"I must warn you, however," He said without taking his eyes off the clock. "that the project was designed for someone with Black Doom's DNA, such as Shadow. Without it, the antigen reacts differently with your body, making the pain ten times worse and longer upon application. And Shadow was out cold after only a single dosage."

Sonic, who could already feel the antigen circulating, gritted his teeth and clenched his fist, trying his best not to show weakness. "I can handle it."

"Can you?" The commander asked and was satisfied to watch Sonic collapse onto the metallic floor, clutching his head in agony. He stopped counting after thirty seconds, when Sonic could no longer hold in the pain and began screaming in pure anguish.

After what seemed like an eternity, Sonic's screams turned to gasps, his voice having been used up but the pain still continuously increasing. A great part of his concentration was into keeping himself conscious and sane over the torture the antigen gave him. Like what he always did whenever he was in danger of giving up, Sonic reminded himself of the reason why he had to stay alive and clung onto that like his life depended on it.

There was no way he would allow himself to die. He was the only thing stopping GUN from attacking his friends. He would force himself to stand through daily – no, hourly – torture and torment of any kind, be it physical, mental, psychological or emotional. He would live through hell and endure everything they'd do to him if it meant his friends' safety and happiness. To him, it didn't matter if he could or couldn't do it, because he had to, and so he would.

Sonic knew deep down, despite his slowly losing consciousness, that the ultimate sacrifice he could make for his friends was not a noble but quick death. The ultimate sacrifice took much more than that. It was to live a life of pain and anguish in the worse possible way and stay alive until you knew that your friends were safe.

That was the sacrifice Sonic was making, and right before he blacked out, he knew he didn't regret it.

EDIT 07/01/2014: Note this is the prologue. A lot of stuff are going to happen, which will be explained in later chapters. Heh.

Just a note: I would never have gotten to courage to try to make this into a multi-chap without the reviews from SuperSonicBoom 12, orion, EliTigre, tailsthefox92, AngelCakes2335, Guest(whoever you are), and ShinyShiny9. Thank you for that, I think I needed it.