It was AC 200, five years after the last war, and Duo Maxwell was missing. Always one to keep in touch with all the other former pilots, Quatre Winner was the one who alerted the others of such. That Duo had seemingly disappeared off the face of the Earth...and the colonies. Heero had been doing some recognizance work for the Preventers at the time, so even he was unaware until Quatre notified him. Nobody had seen hide nor hair from Duo in months, ever since he resigned from the Preventers group. For the first few weeks there was email contact, and then that too dropped off, leaving Quatre with a very uneasy feeling. All his attempts to locate his friend were met with failure. Apparently Duo did not want to be found, but something just didn't sit right with the young Arabian businessman. He'd had that feeling for a while, so he started to search on his own.
There had been an emotional on-again, off-again romantic thing between Heero and Duo that, as of last count, was off-again. Heero was fighting personal demons, trying to "find himself", and figure out whether Duo was really the person he wanted, or whether he was attracted to him simply because of their past lifestyle as pilots and soldiers; children who needed comfort and affection, grasping it anywhere they could. He was still confused. Duo, on the other hand, knew what he needed. He needed someone to love him, no matter who that person was. Things just never melded between Duo and Hilde, and in his sadness, he'd gone back to Heero, who changed the world for him. They were older, they were more mature, and Duo had realized that he definitely could love Heero, if Heero would love him back. Maybe even if he couldn't. It was Heero who kept throwing Duo into an emotional tailspin every time he started to doubt himself. What no one realized at the time was the fact that Duo was battling other personal ghosts as well, so all the upheaval from Heero just made matters worse.
So came the time when Duo had decided that he'd simply had enough. He resigned from the Preventers, giving the reason of needing time to do some "personal exploration", packed up his things and left. He and Heero were at a very cool spot in their relationship at that moment, so Duo's leaving wasn't particularly sad nor unexpected by the other. Neither Heero or Wufei were overly concerned, stating that "Duo was a grown man now and could take care of himself", figuring that he'd probably return anyway. Quatre was the only one who remained concerned about the behavior of his friend, and he bugged Trowa endlessly about Duo's departure, and about the bad feelings he was getting. Feelings that Duo was experiencing a lot of pain that he wasn't letting on about.
When email contact ceased with Duo, after a few months since his departure, Quatre became up in arms and undertook the task of locating him and bringing him back 'home', since everyone else was undergoing assignments for the Preventers. Sure, Quatre was busy too, learning the ropes as head of a large corporate conglomerate. But it was he, of the four, that had the most time available to search. So search he did. It soon became plainly obvious that Duo was nowhere to be found.
Duo knew exactly what he was doing, and where he was going...or so he thought. He needed some time to think. To find himself. To figure out just where his life was going now that there was peace. To come to terms with what Heero had been putting him through. He needed to get away from everyone. There was something in him that kept at him relentlessly. Memories from his past, his long past. Thoughts again of his beginnings and everything he'd been through in his relatively short life and the lives that affected him. The lives the he himself affected as well.
He'd started to have doubts about his actions long before the wars were over, but never gave them much attention until later. He'd always been haunted by the feeling that he was death personified - it seemed to follow him everywhere he went. It made sense to him that he'd eventually wind up a freedom fighter that would entail him to kill even more. He did his best, acting with great zealousness while he was fighting, and after the fact, it all scared him very much. The way he could just put feeling aside and kill like that. It was more than just doing what he was told, or what was needed to achieve a desired result. He'd actually begun to enjoy it. Killing. Then afterward he'd cower in the depression of what he'd allowed himself to do - take pleasure in hurting and killing. He began to think that there was really something wrong with him, because people don't usually lust to hurt and maim and kill the way he had in the past. Beneath that soft exterior and jovial face was the truth - that he was a heartless, loveless killer.
So with that in mind, Duo started to withdraw into himself - the killer. Heero's attentions didn't help matters any either. Before long depression had its foothold, and Duo was having little conversations in his head about what a terrible person he really was to allow himself to do the things he'd done over his lifetime. How could he have let Solo die? He didn't run fast enough. How could he have allowed the Maxwell Church to get bombed, killing the only family he had? He didn't return quickly enough with that mobile suit that could have protected them. How this...how that? He eventually convinced himself that because of his actions, because of things that he either did wrong or did badly, he was being punished. Punished by the deaths of everyone important to him. Punished by being turned into a full-fledged killer. And now, punished by the nonchalant attitude he was getting from the one person that he wanted to open himself up to so that he could try to heal himself.
Feeling that he was totally alone in the world, stuck inside his demented frame of mind, Duo left everything that he had that was familiar to go back to where it all began. He wanted to try to start over again, only this time differently. Without so much as a note, he left the Earth and his job at the Preventers, left his friends, left Heero and everyone else and returned to the streets of L2, looking for...something. He didn't know what. He just thought it was there, whatever it was.
He'd kept in contact with Quatre occasionally, lying all the while about how he was doing and where he was, until the day he hocked his laptop computer for something to eat and a bottle of rum. Duo had taken to drinking in his despair, finding alcohol to be a suitable mind-numbing agent that could, at least temporarily, get his troubles off his mind. He wasn't finding what he yearned for. His soul. He was looking for his innocence, his soul that he'd lost so long ago, so he thought, and he wasn't finding it, which made the depression all that much more present. Without anyone else to help him come to terms with his guilt and his past, now viewed from an adult aspect rather than as the child he was before, Duo slowly began spiraling downhill in his emotional turmoil. There was nobody to pick him back up.
The day finally came that found Duo totally slumped in sadness, inebriated, and angry. Angry that he was himself. Angry at his so-called friends, for not being there to help him, even though they could not have known his troubles. Angry that he'd allowed himself to deteriorate to the point where he didn't care about anything except...being sad. Nothing was cause for any happiness longer than a few seconds, but the despair was ever-present. No matter how hard he tried to change that, some type of sick comfort always came from huddling up with his bottle and his depression and the three would have a good cry together. Or rather, Duo would cry and his bottle and his depression would just watch. At that moment, Duo Maxwell hated himself more than anyone had ever hated himself before. He was drunk. He was dirty. He was useless and nobody cared about him, including himself. It was time to end the suffering that his guilt had bestowed upon him.
His next waking moment was strange, to say the least. He'd woken up in the Police Precinct of L2, incarcerated. He wore handcuffs. He was filthy and his clothing was torn. He stunk of vodka and his head was spinning. Upon questioning the guard on duty that night he'd learned how he'd gotten there. In his drunken depression he'd apparently gone out into the busy streets of the colony during rush hour, screaming at the top of his voice that he was a murderer for the colonies, and how he'd killed fathers and mothers and priests and nuns and children alike. He yelled that if there really was a God, he should be struck down in his tracks to pay for his sins against mankind. Then he'd thrown himself in front of a bus. Much against his little plan though, the bus was preparing to stop anyway, to let off passengers, so he was uninjured barring a few cuts and scrapes. By that point someone had already called the police, and so he was dragged to the Precinct in an alcohol induced depressive rage so much different from the Duo Maxwell that had, only months before, been the proud former Gundam pilot that helped to win the colony wars and the eve war.
He didn't have any ID on him, nor anywhere else, for that matter. He wouldn't give them a name. He kept repeating that "the person that he used to be was dead, so he had no name, unless they wanted to call him Shinigami." After a very loud and exhausting night spent in lockdown at the Police station, Duo was evaluated the next day by a psychiatrist, after his buzz subsided, and was found to be, at least at that moment, mentally unstable. And thus explained the disappearance of Duo Maxwell. Nobody knew where he was. Nobody knew WHO he was. HE didn't know who he was any longer. After a quick court hearing he was placed under the jurisdiction of the colony until someone could get some kind of information out of either him or a relative, and he was removed to the L2 Colony Ward for Mental Patients, a government funded institution.