One day, her older brother came home from a long day of school, and Yagami Sayu knew something was different.

She watched him make his way up the stairs, technically present but his mind elsewhere. At the time, Sayu had thought very little of it, and had gone back to playing video games. Light was intense, and took himself very seriously. No doubt his future was on his mind.

A few days later, he was still different, but something had further changed. He seemed more confident, in control, less preoccupied – at the same time, thinner, and slightly ill. Sayu carefully watched him, when she was sure he wasn't paying her any attention (not that he normally did, unless she made sure of it), and she eventually arrived at the conclusion that this wasn't about school, as most things in Light's life were.

Light was the oldest child, the one always at a stage that his parents were unsure about. And so they put a great deal of pressure on him to be intelligent and perform perfectly, which he did. Thus, they were assured they were raising him right.

Sayu was the youngest child, the one going through the stages that Light had already passed through – they knew what to do with her, and they felt relaxed enough to give her freer reign than they had given Light. Sayu flourished and ran wild where Light had been rigidly contained, pruned and cut into a specific mold, for fear of letting him take the wrong shape.

Sayu had always thought it was very silly of them to think that all geniuses would act and present themselves like Light – they were all so different in personality, after all, and there was such variety in the world, in their upbringings, that they surely would all be different. She didn't want to go so far as to say that she was proof of that, but she wouldn't be surprised if that turned out to be a correct assumption.

She didn't care about school, not like Light had to – she got good enough grades to make sure she didn't get in trouble, but it really wasn't the most important thing in life. Light had been taught to value all the things his parents did, which were societal concepts, like justice, academics, prestige and honor. At the age in which Light was being praised for his genius openly in class, rigorously made to memorize and challenge and prove himself constantly, Sayu was allowed to run off and play, stagger through the park, get bored playing with other children, and find her way to the library to read Nietzsche, Kant, Suzuki, Lovecraft, Poe, textbooks about quantum physics and philosophy, treatises on religion, and instructions on how identify the components of stars from the colors in their light.

Why, when the universe was so big and so incomprehensible, would she give a damn about her own intelligence relative to that of billions of other, equally tiny humans? Life was short, after all – too short to worry about petty little things like politics or crime or academic success. Flowers were blooming, the sun was shining, and who knew if any of them would be around to enjoy these things tomorrow, so why not enjoy them today?

If her parents knew how smart she really was, they would try to turn her into Light – and Light, whether he himself knew it or not, was miserable. And so she carefully kept it a secret, hidden and locked away from the rest of the world, even though she wanted to scream the truth from the rooftops and tell them all that it was pointless to keep living their lives this way.

Thus, when this development came to her attention, Sayu realized that Light must have found something more worth his time than school and pleasing their parents. She resolved that whatever it was, she would find out. Her brother had found a reason for existing that he wasn't telling Mom and Dad about, and she wanted to know what. Maybe, finally, she would be able to share her thoughts with him – lift him above the inanity, the human structures that they had drilled into his mind, and together they would soar in the stratosphere, discussing concepts like destiny and kindness like the intangible things they were.

Sayu was a happy person, but it was lonely in her world full of poetry, bright colors and strange, wonderful ideas. If she could share the space in her mind with someone, anyone, that would be the day she knew herself to be truly happy.

So one day, while Light was out, she searched his room. Sayu knew all about his many safeguards – from the pencil lead to the door handle, she carefully bypassed them all, down to the last millimeter. He would never know she was there.

She discovered the false bottom to his drawer when she saw the pinhole on the underside (she'd taken them out of the desk, looking for carefully-hidden documents pinned to the back of the drawer – she had several hidden in her own room, written in code and carefully concealed in the same way). Guessing at what the pinhole was for, she compared several items on his desk to the hole's size, until she realized that it was just the right size for an unscrewed ink cartridge. When she decided she had found the right pen, Sayu used it to lift the false bottom.

The first thing she noticed was not the script on the front of the book (her English being rusty), but the mechanism he used to hide and protect it. The wires, the bag of gasoline... She hesitated before taking it out. Light was willing to risk both his own and his family's lives to keep this secret. Whatever this was, he thought it was more important than anything else. What are you up to, big brother?

Sayu rolled up her sleeve, copied the words on the front cover and the following pages onto her arm with a marker, and then opened the rest of the notebook.

Inside, thankfully, was Japanese. There was a long list of names – none Sayu recognized. The next six after the first one seemed to be variations on the same name, and all had the words 'car accident' after them. The rest were alone. After the third new name, the writing became quicker, more close together, as if Light had become more sure of what he was writing down. Sayu took note of as many details as she could, noting especially the name furiously scrawled across one page in English. It was odd, she felt like she'd seen it before...

And then she shut the notebook, and put it away exactly as Light had left it. His bedroom looked untouched when she closed the door (leaving the door handle in precisely the position Light always did, replacing the paper and the pencil lead), her mother was busy in her home office, and her long sleeve hid the notes she had taken.

Sayu wouldn't tell her parents about the gasoline – indeed, she planned from the beginning not to tell them anything about what she found. She came from a family that kept secrets from each other, whether the rest knew of that or not, and she could keep hers better than anyone.

Besides, it didn't really matter. Nothing really mattered, unless Sayu chose to assign meaning to it. That was the beautiful thing about her philosophy – it didn't obligate her to care.

Late that night, computer muted and translation software on the screen, Sayu decoded the English words in the book.

Death Note

The human whose name is written in this note shall die.

Sayu might have thought Light had made the book himself, in English to keep their parents from reading it – he was a very resentful person, after all – but for the fact that it was on black paper, with white ink, and not in Light's handwriting. Written, somehow, on black paper, with white ink. A chilling thought by itself. And even if he had made the book, and it was really nothing more than something to exercise frustration on, why did he hide it such a risky manner?

This not will not take effect unless the writer has the person's face in their mind when writing his/her name. Therefore, people sharing the same name will not be affected.

If the cause of death is written within 40 seconds of writing the person's name, it will happen.

What if someone wrote the name, and then, within 40 seconds, someone else wrote the cause of death? Would that count? And what if the cause of death was written first? Sayu knew Light hadn't made this – there were too many loopholes; if he'd come up with the rules, he would've made them clearer. So whose invention was this? Someone on the internet? Was this a trend going on that Sayu was unaware of?

If the cause of death is not specified, the person will simply die of a heart attack.

Well that was a silly default to have. Not everyone was in danger of heart attacks – most people who had heart attacks already had weak hearts. Wouldn't it be simpler if they just died of the nearest potential accident? Those were far more common than heart attacks – and less suspicious, if the subject was healthy. This had to be a joke notebook going around – whoever had made it hadn't had the slightest idea what they were doing.

And yet – Light had hidden it in such a dangerous way... What could explain that?

After writing the cause of death, details of the death should be written in the next 6 minutes and 40 seconds.

There was something she was missing here, Sayu was sure of it. But she took a wet towel and washed off her notes, deleted the translation, and went to bed. She would sleep on it – tomorrow, she might remember what it was.

Kira. Of course.

At lunch, one of her friends had doodled Lind L. Tailor's name in their notebook, in English and Katakana. Sayu had only heard the name on television while she was in another room, just before Kira killed him – she had rushed in to see what was happening, and the screen had already cut to L's real announcement.

Sayu had hoped that Light had found something, a hobby that would truly challenge and delight his intellect, distract him from the ills of society that plagued him and their father. But no, he had found something much worse, something that would only take his false idea of justice and twist it to hurt himself and others. This could have been an intriguing mystery, something to investigate with science, an experiment Sayu would have been all too happy to participate in, but Light (Kira) only seemed interested in using it. It was no wonder that her brother had begun to look sick.

When she went home that day, and saw a tall, dark, frightening figure floating behind her brother, her heart almost stopped, then started beating like her life was in danger.

Sayu had quickly looked away, but made it look casual, like she was looking down to kick off her shoes. Light was acting normal – she better act normal too. Whatever it was, it might not want anyone to see it. Knowing what Light had in his desk, it might well be the Grim Reaper or something, and Sayu had no desire to risk incurring the wrath of a supernatural being.

(She did, of course, consider that she might be hallucinating. But such things either tended to run in families, or be triggered by something else, like immediate trauma or hallucinogens. The former was untrue in her case, and the latter seemed highly unlikely. Besides, this was too coincidental, after having just discovered Light's secret – and Sayu wasn't such a rigid thinker as to deny the possible existence of such beings.)

The real question was, how could she see it? Sayu observed it carefully in her peripheral vision, always making sure to be focusing on something else as she and Light set the table.

It had enormous feathered wings, but it didn't seem to be using them much, only making the apparently minimal effort it took for it to float. Its face was almost human-like, but its expression was perfectly blank as it surveyed the room, scratching its side. If it were human, Sayu would have interpreted its body language as bored.

At some point as they were eating (while Sayu kept stealing glances at the monster), it began to chuckle.

She hadn't even recognized it as laughter at first – it had taken every ounce of her self-control to keep from screaming when she heard it. Out of the corner of her eye, she saw Light jump very, very slightly. So he could see it too.

"Funny," it said, its voice like the wind lifting dust across a field. And then it became quiet again.

Light was tense for the rest of the meal. Sayu could practically feel his mind racing, trying to analyze what it meant by that. How much did he know about the creature? If it could speak, did it speak to him? How long had he been seeing it? When had it come to him, started following him?

Was Light in danger?

It wasn't long before she saw it again.

Sayu was completing her homework before bed (she preferred to rest after school, relax with books, manga and other distractions, then do her homework at night. It took minimal effort to get average grades, and she knew how to cover up the bags under her eyes). Only her desk lamp was on, and her room was dark.

It was hard to focus, knowing the creature might still be in the house. Was it with Light? How could he sleep if it was? Was he asleep? Did the creature sleep? What was it?

"Hi," said a voice above her head.

Sayu stifled a screech – and looked up.