A/N: I have no way to contact non-logged reviewers other than this, so here's a note to say thanks for taking the time to leave a comment! Hope the rest won't disappoint.

It was in old days, with our learned men, an interesting and oft-investigate question, "What is the origin of light?" and the solution of it has been repeatedly attempted, with no other result than to crowd our lunatic asylums with the would-be solvers. Hence, after fruitless attempts to suppress such investigations indirectly by making them liable to a heavy tax, the Legislature, in comparatively recent times, absolutely prohibited them.
I-alas, I alone in Flatland-know now only too well the true solution of this mysterious problem; but my knowledge cannot be made intelligible to a single one of my countrymen; and I am mocked at-I, the sole possessor of the truths of Space and of the theory of the introduction of Light from the world of three Dimensions-as if I were the maddest of the mad!

The door opened with a slight creaking sound, the lock having given in to his pin with a clack. Bill paused for a moment, listening for the slightest sign anyone had heard, but there was nothing, and he pushed the door open just enough to slip inside of Liam's room.

Everything was like it had been last time he had seen it. The remains in the book he had chewed on were in the bin near the bed, where Liam had let it drop. Everything else was undisturbed, nothing out of place. No signs of a fight. Either his parents had tidied up the room before locking it up, or Liam had offered no resistance.

Bill wasn't certain which option was worse, and he resorted for not thinking about it. He was there for a reason, after all.

He steadied his resolve, and closed the door behind himself as quietly as possible.

There were several shelves filled with books in Liam's room, but none of those seemed out of the ordinary. Nothing like the one he had read, that was certain: even he could tell that book was not supposed to be in anyone's possession.

It had taken him several nights to go through it - not due to being a slow reader, but because he would pause at each page, eye wide, trying to wrap his mind around what he was reading. Was there really another world out there - even several others? Three-dimensional ones? He couldn't even begin to imagine what a third dimension would entice, as he couldn't even begin to imagine what this thing called color would look like. He had never heard of it before now, couldn't even imagine it, but the thought alone filled him with more longing than he'd ever felt before.

What if he could actually visit this place, this third dimension? Would it be the kind of place where everything was possible, where things could truly happen by chance and not be considered a mistake?

… Would Liam's irregularity not have mattered in a such place?

Bill was snapped from such thoughts when his hands finally found something - the edge of a loose board on the wall behind the head of Liam's bed.

Not a bad hiding place, Brainiac, but predictable.

It came out of the wall with little effort, and there it was - a pile of books. Most of them were on old theories on the existence of light, or recounts of the Chromatic Wars of old, and yet more things he had never heard of. And at the very back there was a notebook filled with… wait, were those numbers?

A noise somewhere outside startled him, and he quickly took the books out before placing the board back in place. He had a similar hiding place in his own room, though for now he had only used it for sweets, and he supposed it would do. He didn't want to get in Liam's room even again, but what he had left behind was coming with him.

When Bill returned to his room he was staggering slightly under the pile of tomes. He was tired, his eye scratchy with the lack of sleep, but it didn't matter. It didn't matter at all.

He had a lot more to read about, and a code to break.

How admirable is the Law of Compensation! And how perfect a proof of the natural fitness and, I may almost say, the divine origin of the aristocratic constitution of the States of Flatland! By a juidicious use of this Law of Nature, the Polygons and Circles are almost always able to stifle sedition in its very cradle, taking advantage of the irrepressible and boundless hopefulness of the human mind.

"Therefore, when it comes to contracts, you ought to make sure both parties- Bill, are you listening?"

Bill's eye snapped open, and he found himself facing his father's worried look over the accountancy book they were going through at the shop's counter. Well, at least the one they were supposed to be going through. Bill had dozed off… at some point, he guessed, though he wasn't sure when. "It wasn't something about cheese houses, was it?"

His father frowned and reached to rest a hand above Bill's eye. "Are you ill, son? I've been wondering for a while now. You seem tired. Aren't you sleeping well?"

Well, no. Forbidden books to read, a code that refuses to be cracked and thinking of other dimensions at night with make it kinda difficult for you, Pops. Rebellious phases are tiring.

Of course, that answer was so out of question it wasn't even funny. Bill just shrugged.

"I'm okay. Just not sleeping too well," he said. Truth was that, even if he wasn't that tired, he probably wouldn't have been interested anyway. Learning how to deal with clients was fun, and he was good at it - even more so when there was some haggling or downright swindling to go - but now there was so much more on his mind. Focusing on something like that seemed just impossible.

Relief was plain in his father's gaze. "Good. But if you're feeling ill, tell me and I'll take you to a hospital for good check-up. Better safe than sorry - don't know what I'd do if anything happened to you."

But you let them take Liam away.

Bill forced himself to chase away the thought. "I'll put you through something worse. I'm staying right here," he said. For now, he thought.

Because he would find a way out of that world, if it was the last thing he'd ever do. He'd make it out, see the world of three dimensions, and watch the colors until his eye was too tired to look on anymore. He'd see it all, for both of them.

Until then, he'd bid his time.

Even the utterance of any word denoting Colour, except by the Circles or by qualified scientific teachers, was punished by a severe penalty. Only at our University in some of the very highest and most esoteric classes-which I myself have never been privileged to attend-it is understood that the sparing use of Colour is still sanctioned for the purpose of illustrating some of the deeper problems of mathematics. But of this I can only speak from hearsay.

Hi, Bill.

Bill froze, eye fixed on the words he had just written on the otherwise blank sheet of paper. His gaze moved from it to the other sheet of paper, one covered in numbers he had found wedged in the notebook and that he had used to try cracking Liam's code. And now - after yet another sleepless night, crumpled-up remains of his previous attempts on the floor all around him - he knew he had found the right key to decipher it.

That sheet was not part of Liam's notes. It was a letter.

Hi, Bill.

If you have found this, I assume the Inspection went as I expected it to, as I was no longer able to destroy it. It gets kind of tiresome, writing your last letter anew every week. I'll be relieved when I no longer have to do it, whatever the outcome may be.

If you have found this, then you have also found my books. I knew you'd come snooping around, sooner or later, and that if someone were to decipher my code it would to be you. You're such a pain in the angle, Bill. Never giving up. Not even on me.

There is not much else to add, and I'm not good with words - you always did enough talking for us both. All I know is in these books and in my notes. There is something out there, something so much bigger than you or I could even imagine. A whole universe of possibilities, and some chosen can even visit it. The Circles are all too aware of it, but this knowledge is forbidden, as I'm certain you must have worked out by now.

Whatever you decide to do with this knowledge is up to you. I can only urge you to be careful. And if you ever get a chance to see what I can only read of, promise me you'll take a good look for both of us. I always wished I could see the colors.

Neither of us was supposed to happen, by all accounts. We defy logic as this dimension defines it. Perhaps it wouldn't be too crazy to think you might take it a few steps further. You're weird enough to do it - Irregular as I am, just as unfit for this world, but they can't see it. An undercover Irregular, if you will. It is a good cover you have. Don't shed it.

Stay safe,
Liam.

He read it again and again, until he was no longer sure it was tiredness that made his eye burn. Finally, he folded it and placed it back in his hiding place, where he kept all the books and notes he had taken from Liam's room.

A day would come when that letter and the books would be lost amidst chaos along with the rest of their world, but not just yet.

I declared that I could say nothing more, and that I must commit myself to the Truth, whose cause would surely prevail in the end.

"Hey, old man. You're gonna break in two if you keep that up. Ain't it time to retire?"

The elderly shopkeeper - whose name, while rarely used, was Randall - looked up from the pile of books he was putting back in place. There was no sign of recognition in his eye, but Bill was not surprised. It had been quite a while since last time he had seen him, and he had gone from a kid to… well, not fully an adult yet, but close enough. Old enough to demand answers, either way - more than what Liam had left behind could give him. He had spent years memorizing every last line of his books and notes; now it was about time to step up.

"May I help you, sir?" Randall asked, setting the books aside. He had looked old last time, but now he looked positively ancient.

It would be a long time later that Bill would revise his concept of ancient. Still unaware of it, he just shrugged. "Think you might, yeah. Good thing I came in right before the bookshop closed, huh?" Bill said, taking a look around. No one was in there except for the two of them.

Perfect.

"But the shop is not-"

"It is now," Bill cut him off, and closed the door behind him. A turn of the key, a flip of the sign, and he knew no one would bother them. He liked distractions - liked them a lot - but they were best when they didn't get in the way of business. Not of his business, anyway. "Gotta love it when timing works for you."

The look in the other's eye went from perplexed to alarmed. He stepped back.

"If you mean to steal from me-" he began, only to trail off when Bill waved his hand.

"Whoa, whoa, stop right there. Hey, heard that?"

"Heard… what?"

"My heart shattering in itty bitty pieces, that's what. Is this how you greet an old friend? Calling him a thief?" Bill sniffled in mock hurt. "I don't steal, old man. I make fair deals. Aaand occasionally swindle an idiot or two, but usually everyone's happy."

The older Triangle seemed to relax, but only slightly. "Then… I am sorry, sir, but I don't know who you are. Forgive an old man's failing memory and remind me."

Bill reached to tip his hat - a gift from his father, and a predictable one, since trinkets like hats and ties were what he sold for a living; at least no one could accuse them of being anything less than snappy dressers - and gave a mock bow. "Name's Bill Cipher. Ring a bell?"

It clearly did, for Randall's eye widened. "Oh, Circles - Billy? Is it really you?"

"... Did I stutter the 'name's Bill Cipher' part? Was sure I hadn't. I rehearsed it and all before coming in."

Randall finally laughed, but it was easy to tell it wasn't a wholehearted one, and Bill could very easily guess the reason why. "No wonder I didn't recognize you, then. My, how you've grown. I hadn't seen you since-"

"Since Liam was taken. He didn't get to open his surprise, in case you were wondering. I did, though. I sure was surprised, I can tell you," Bill cut him off, leaning on the wall, and he wasn't at all surprised now, when Randall took a staggering step back. "See, this is why it's lucky for both of us this store is closed right now. Can't really discuss your dealing of forbidden books in front of the public, can we? I mean, we could, but then we'd wind up imprisoned or worse before we can even finish, and that would be one major pain in the angle."

"Billy-"

"Bill, thanks. And… look, can you stop staring like I'm gonna bite you? It's kinda distracting."

"Uh… sorry."

"Thaaat's better," Bill said, and reached to put a hand on his back, leading him further into the store. "Now… where was I again? Oh, right. Liam's surprise. Nice trick, that - made me think there was a joke going on that I was part of. You knew telling me anything else would have been an invitation for me to open it, huh?"

"But you did open it."

"Liam wasn't there to do it anymore by the time I returned. May have just missed him. Maybe I wouldn't have if I didn't have to stay and put your dumb books back in place, but hey - then they might have checked out the book and none of us would be here today. I kinda like being alive. So let bygones be bygones and tell me - did you get Brainiac more of those books? I found quite a stash in his room."

Randall drew in a deep breath. "If you speak of this with anyone-"

"Haven't so far and won't start now. I ain't my brother, Randy, but I ain't dumb either. Getting myself locked up for isn't among my short, medium or even long term plans. There are things I'd like to do before that. Seeing the colors, visiting this Third Dimension, give the Big Chiefs of this dump of a world a lesson, learn to play the piano. In no particular order."

There was a moment of silence, then Randall gave an odd sort of laugh. "I did wonder if those books would ever be found after Liam was gone, but I took all steps to make sure they could not be traced back to me. I didn't expect fate to interfere and lead you to it."

"Not fate. Chance," Bill corrected him. "Thanks to your amateur mistake of using me as a middle man. Should have sorted out your business on your own instead of relying on a kid. So, it was you to provide the rest of them."

"Yes. Being an Irregular, Liam was often watched. He couldn't join us here, but he wanted to know - so I took steps to take the knowledge out to him. He understood the risks, but-"

"Hey, hey, rewind," Bill said, stopping in his tracks and forcing Randall to do the same. "Us?"

Randall turned to face him in full. He had done the same last time they had met, but this time Bill stood just as tall. "You and I are not the only ones who know about the Third Dimension. There are more like us scattered all over this world, and more texts to be found, to comprehend. This shop is one meeting point, the one closest to the capital. I can introduce you to it, Bill, if so you wish. But you need to be certain."

Bill straightened himself. "Sure I am. Certain is my middle name."

"Wasn't it Norman?"

"... We're not talking about that."

This time, Randall's laugh sounded more sincere. "Very well. We meet the second Thursday of each month after closing time - that will be next week. We'll share all we know of the Third Dimension with you. You will need to knock thrice, and bring something with you."

"Oooh, get it! Like, a token of commitment or something? The heart of an enemy? Their eye? A pound of flesh?"

Randall blinked. "No, I- I meant something to eat or drink - what in the Circles is wrong with you?"

Bill rolled his eye. "You guys suddenly sound a lot less fun."

"We're not here for fun, Bill. It is for knowledge, and for the hope of a better future, of a free world."

"... And food and drinks."

"Those can never hurt."

"You've got me there. Hey, I can make great Martini. Would that work?"

"Oh, absolutely. And, Bill?" he added, putting a hand on his back. "We have yet to unlock the mysteries of the Third Dimension, and if there is a way for anyone to go there - anyone but the lucky one chosen by the Sphere at the turn of the Millennium - we have yet to find it. As of now, we lack the power to change what ought to be changed in this world. But there is one of your wishes I can make come true right away."

"Can you teach me how to play the piano?"

"... That, too. But I was referring to something else - something whose secret we mastered recently enough. I can show you colors, here and now."

And if you ever get a chance to see what I can only read of, promise me you'll take a good look for both of us. I always wished I could see the colors.

For a moment, Bill could think of nothing to say; an unusual occurrence, that. When he heard himself speaking, it felt as though his own voice was coming from a mile away.

"... Show me," was all he said, and followed Randall in the back of the shop, and then through a movable shelf.

Elsewhere in Flatland, Colour is no non-existent. The art of making it is known to only one living person, the Chief Circle for the time being; and by him it is handed down on his death-bed to none but his Successor. One manufactory alone produces it; and, lest the secret should be betrayed, the Workmen are annually consumed, and fresh ones introduced.

His eye hurt, but he couldn't look away.

Dimly, from very far away, he heard Randall saying something on how he shouldn't stare too long, how the untrained eye might find the sight too hard to bear. He said something on needing time to adjust, but Bill didn't listen to one single word.

Before him, on a section of the wall at the end of the room, were splashes of color - of all sorts of colors. Some were darker and some more vibrant, and his eye was drawn on the brightest of all, the one that was painful to look at.

A day would come when Bill Cipher would know the names of each color in all languages ever conceived in any dimension existing. In a dimension close enough to his - and yet so very far - the color he was staring would someday be known to some as 'yellow'.

To Bill Cipher, right there and then, it was simply the first true glimpse at a wider universe.

I glanced at the half-hour glass. The last sands had fallen.
The third Millennium had begun.