Author's Note

Hello again everyone. Just a few explanations before I get to the story. (and I'm still working on that one-shot collection-didn't realise it would be so hard to write) First of all, this is an AU crossover between Digimon Frontier and Darker than Black. For those unfamiliar with Darker than Black, main parts will be explained in due time. But if I miss something, don't hesitate to ask, and I'll get back to you as soon as possible. Just don't ask about the Doll/Contractor stuff, because that's a later chapter.

Secondly, the title of this story, Nakushita Mono o Torimodosu Toki, translates to "When you recover something lost", and is partly named after one of the Darker than Black episodes.

Thirdly, this is the first time I'm trying something like this, so opinions will be welcome.

Fourthly, this prologue takes place eight years before the actual story (and the Darker than Black series), so keep that in mind.

Fifthly, there are a few changes with ... things. The twins are living together in Shibuya. You'll find out the parental situation later. Also, they, in this prologue, are eight years old. So in the actual story (starting from chapter one), they are sixteen.

Disclaimer: I don't own Digimon Frontier or Darker than Night. I'm just a weird girl who likes weird things. Ask my friends, or even my teachers if you don't believe me, they'll even tell you I'm weird (in a good way though).

Wow, that's a long pre-story note.

Nakushita Mono o Torimodosu Toki (When you recover something lost)

AU x-over with Darker than Black. By day, he's the 'lone-wolf', transfer student. By night, he's one of the most feared assassins in Tokyo in search for the brother he lost long ago. But what happens when he finds him, on the other side...

Kouji M & Kouichi K

Prologue – As His Last Smile Fades

It had been two years since the Hell Gate appeared. Two years since the natural sky vanished, only to replaced by the darkness that now spread over Tokyo, and perhaps beyond, littered with stars, that would sometimes shoot past at an occurrence at death.

Minomoto Kouji knew no more than that, and despite the dangers that had emerged with the Gate, there was something about it that intrigued him. The power it held, and even through the darkness of the night, he could see the distant glimmer of light that signified its spot of emergence.

And that power, across several districts in the very heart of Tokyo, at the point of the emergence of the Hell's Gate, was calling out to him.

'Kouji-kun?' He turned, seeing his elder twin standing in the doorway of their family home, a green short-sleeved jacket over his normal outfit to protect him from the slight chill. 'Why are you out here alone 'Touto-chan?'

'Just thinking. About the stars...and the Gate.'

'You think about them so much...does it feel like it's calling you?'

'What is?'

'The gate...or something in it.'

'I...yes, it does. But how did you know?'

"cause we're twins silly...'sides, I can feel it too...'

They smiled, identical twin smiles. The two brothers, arm in arm, stared out into the sky, past the shroud of darkness that hid the night sky, searching for what was calling them.

Kouji yawned, an action that was mirrored by his twin. 'Shall we go in, Kouichi-nii?' he asked, as the other rested his head upon his shoulder.

'Mmm...let's stay a little longer,' Kouichi mumbled into his brother's blue jacket.

Grinning more broadly, Kouji wrapped an arm around his elder twin. 'Alright,' he assented, closing his eyes. 'A little longer.' Sleep peacefully big-brother. May no more demons plague your sleep.

'You think Kaa-san is watching over us 'Touto-chan?'

'I'm sure she is Ni-san.'

Kouji's eyes flew open only minutes later to his brother's scream, only to find one hand clutching the green short-sleeved jacket, still warm from his brother's body heat, but his brother no-where in sight.

'Kouichi!' he yelled into the darkness of the night. The only reply he received was another, more desperate scream.

'Kouichi!!' he screamed louder, running into the house, following the sound of the screams, and almost crashing into his stepmother, Satomi, as he ran around a corner.

He could hear his stepmother's footsteps behind him as he ran into a room at the end of the hallway. His brother's room, since he had come to live with them once more. Their parents had divorced when the twins were two, his mother, Kimura Tomoko, taking the elder twin with her to her family home in Shinjuku. Unfortunately, her father died the same year, of a stroke, her mother only living a year more before she too passed away. Tomoko and Kouichi lived alone after that, Kouichi never knowing about his father nor brother. She worked hard to support him; too hard, as eventually she pushed herself too far, her already heart giving out.

Upon her death, Kouichi was taken to his father...to a family he barely remembered. Minomoto Kousei had remarried during the three years they were apart, and like his ex-wife, kept the existence of his twin from Kouji.

It was strange at first, Kousei having to own up to the secrets he had kept, and the lies he had told to his younger son, as well as the twins having to live together after three crucial years apart. But it all worked out in the end. Mostly, except for the elder twin's occasional night terrors. But that was understandable; he had seen the death of three people close to him in his young life...but perhaps it was something else that plagued him.

And now...

Kouichi's room was a complete mess, books, papers and clothes scattered about. The window was open, curtains fluttering, blowing the lighter objects around. Unrecognizable shadows loomed on the walls: monstrous shapes, looking as though they were ready to devour anything. Already, the mortar of the walls was crumbling behind the shadows, the foundations of the room weakening. It was only a matter of time before the roof collapsed.

And a small trickle of blood ran along the ground.

'Kouichi!' he screamed desperately, as the panals of the roof came tumbling down. Satomi grabbed Kouji's shoulders and dragged him out through the hallway, bumping into her husband on the way.

He looked scared, which just scared the other two further. Kousei was a man that feared few things, and the fact that he felt fear know served to magnify the danger.

'There's a Contractor here,' he whispered.

That word meant nothing to Kouji, but Satomi paled several shades at the statement.

'A Contractor? What do they want?'

'They do not always want something. Most kill for no reason at all.'

Kill? Kouichi-nii dead?

Tears spilled from Kouji's eyes at that, as his parents dragged him to another part of the house. Cracks were now starting to form on the outer ceiling and walls, the caved-in room putting a dent into the house's foundations.

That didn't matter to Kouji though. All that mattered that his brother was gone, gone to where his real mother was. He never paused to consider the fact that he may still be alive; it seemed quite improbable, since the screams had come from the room, and the only way out would have been the window. The window leading to a world where a lone eight year old would not last long at all with the Contractors and their Dolls on the loose.

Kousei stopped suddenly, causing Satomi to nearly walk into him. 'The Contractor,' he hissed between his teeth, shielding his wife and remaining child behind him, as he faced the masked man before him. He, like Kousei, was not alone; it seemed as though he had brought a doll along with him, one who was responsible for the shadows looming above them.

Kousei shoved Satomi and Kouji back into the collapsing hallway, just as the entrance collapsed, trapping himself in the dining room with the Contractor and Doll pair.

Alone, and powerless, it was a short fight, and neither Doll nor Contractor had any inhibitions of killing an innocent man. And the two were soon set their task on the two that remained. Or rather the Contractor did; the Doll was simply a medium, once a human, now simply a mere shadow, following his master's orders.

It seemed as though darkness was the Doll's medium, very bad luck for both Kouji and Satomi, as the sky was full of it, as was the house, only a singular bulb still lit. Fading into the darkness, he reappeared a moment later in the crumbling hallway, blocking any means of escape, as the darkness descended upon them.

Kouji squeezed his eyes closed. Even at the age of eight, he feared the darkness, not sleeping without his nightlight, even though he was strong in almost everything else: academics, sport, emotions... Whimpering in fear and grief, he begged the light, that flickering light bulb, to somehow help him. To become a barrier, a shield...anything to prevent the onslaught of darkness that was about to descend on them.

'Enough of this! Identify yourself, Doll!' someone yelled, and suddenly, lightning filled the hallway (or what remained of it). Arms grabbed the eight year old, lifting him up, away from the destroyed home, and his dead parents.

The Doll didn't follow, even as the Contractor yelled from the other side.

'I am Dusk,' was all he said. 'Remember that.'

Kuro no Shinigami stared at the boythat he, with his sister, had just rescued from the ruins of his home. Not any boy either, but a Contractor, one unaware of his power over light molecules.

'W-who are y-you?' the boy stuttered. That was understandable, after all, he had gone through quite alot in the last few minutes.

'I am called many names,' the masked man replied. 'I am called Kuro no Shinigami by some, the Black Reaper. But my allies call me Hei. And what's your name child?'

'Minomoto Kouji.'

'Well, Minomoto Kouji, you feel the call of the Gate?'

His brother had asked him the same thing. 'Yes...but how did you know?'

'The Gate calls those who have a special kind of power,' he explained slowly, so the child could understand. 'You have that power, and now the enemy has killed your parents. You survived, because you have power over light particles, and were able to form a shield. But you must learn to wield your power. We, the Syndicate, can help you with that, if you join us.'

'But...what about Nii-san? Is he dead too?' The way those blue eyes looked up at Hei was adorable, and even the Black Reaper's hardened heart had to soften at the sight. 'I do not know what happened to your brother,' he replied as kindly as he could, 'but I know he is not dead. There were only two bodies in the house. He's still out there somewhere.'

"Tou-san and Kaa-san?'

'They are dead. I'm sorry.'

He was silent. It was too much for his eight year old heart to handle, and he fell into a fit of crying into the shirt of a complete stranger. Despite this, Hei held him close, knowing the bond between the brothers was likely to be as strong as the bond he shared with his sister, who at the time was scouting the area.

'I have a sister too,' he said softly. 'Her name is Bai, and she is the reason I joined the Syndicate. Not all Contractors are evil; those in the Syndicate strive for peace.'

Bai, also known as BK-201, arrived, closing the door of their temporary hideout behind her. 'No sign of them,' she sighed, going over to her brother. 'They're gone.'

'No,' the boy in Hei's arms whimpered. 'They killed them...'Tou-san, and 'Kaa-san...and Kouichi-nii...'

'You're brother's not dead kid,' the Contractor that had just saved him cut in. 'He's still out there, and we're going to help you find him.'

'You will?' he asked, pulling away from Hei slightly, his eyes filling with hope.

Bai nodded, and ruffled the other's hair in a caring manner completely foreign to other Contractors, but normal for her. 'We know how important family is.'

'And those others? Will they pay for what they have done?'

Hei nodded grimly. 'Of course.'

He stepped back slightly, supporting himself and standing straight. 'Will you teach me to control my power, so I can avenge my family and find my brother?'

The two nodded.

Kouji paused. He knew he was treading dangerous waters, accepting an invitation into an organisation he knew near nothing about. But what other choice did he have? No family, no home, no guidance...these strangers were the only people he had left right now.

He bowed his head slightly, expression hardening, and said the words that changed his life forever. 'I will join the Syndicate.'

Post Author's Notes

Japanese Words and Phrases

'Touto-chan/Otouto-chan: younger brother

nii/Ni-san/Onii-san: older brother

'Kaa-san/Okaa-san: Mother (note: Kouji also calls his stepmother this, since she is the one who essentially raised him)

'Tou-san/Otou-san: father

Notes:

Contractors: individuals who have gained power due to the presence of the Heaven's and Hell's gate (will be explained later). They are, unlike dolls, actually capable of experiencing emotion, but these emotions don't impact on their judgement. Many Contractors are part of criminal organizations and are ruthless assassins, which is what Kousei was referring to. More about Contractors will be explained in later chapters.

Dolls: emotionless "mediums" created to mimic the forms of humans. They are essentially programmed to be incapable of emotion, but are able to act outside their initial programming. They are only powerful in the presence of their own medium.

The ending: If your thinking that Kouji's decision is kinda hasty, just remember that he just lost his family, and these two people who saved him from the rubble and the Contractor/Doll pair are the only people he has now to help him. And he's still at that age where kindness plays a large role in convincing him, and both Hei and Bai are kind in nature (at this point in time anyway).