When you live on a space ship, how do you tell whether it is day and when it is night?

Rose often mulled this question over in her mind when she was supposed to be sleeping, but just couldn't find it in herself to relax enough to let sleep take hold. Of course there was an easy explanation. There was no sun and no moon. There was no night and no day on the Tardis. That was the easy answer. The easy answer is generally enough for most people, Rose included, but while in bed, she found she just kept coming back to that same question.

She laid on her bed, examining her ceiling for nothing in particular, and contemplated that question. Was it night time when her clock said 10:32 pm? Was it night time when the Doctor hustled her off to bed, stating that she'd need her beauty rest for the next adventure? Ordinarily those things would both indicate that she was well into night time.

The temperature was comfortably warm in her room. Maybe a bit too warm as her sheets were now in a tangle around her legs. She wore a loose peach tank top and a pair of gray cotton shorts which were both in varying levels of disarray.

Perhaps it didn't matter. If you slept when you were tired and got your rest when you needed it, why would you need day or night? When you lived in a time machine, you simply went where and when you needed to go.

She wasn't sure how long she'd been in bed. Her consciousness moved in and out of a waking dream state. She would fall asleep only to jerk back into wakefulness when she'd witnessed something particularly distressing or impossible.

Maybe tonight just wasn't her night for beauty rest.

Rose sighed and kicked her legs until they were successfully separated from the bed sheets. She stood up and threw a light dressing robe over her shoulders, loosely securing it around her waist. After tracking down her slippers left somewhere around her bed, Rose left her room.

Standing at her door, she looked left and right. Either way, the halls of the Tardis were softly lit and curved so that Rose could not see after a couple of feet down both sides. The air outside her room was just as pleasantly warm as inside. She closed her eyes for a moment and let the sensation caress her exposed calves, chest, and face. Maybe it was warmer than she thought or maybe the air was pleasantly heavy, like an unseen embrace. Maybe the Tardis knew exactly the temperature and humidity that was perfect for her at this moment and this space.

A small smile tugged at her lips at the last thought and Rose turned to start down the left path.

It may have had all the makings of her night time, but she was quite sure that the Doctor would be well into his afternoon. As she made her way towards the console room, Rose's smile grew by a couple of degrees.

She spent all her time with the Doctor but every time they met, even after the briefest period of absence, there was still a little flip in her stomach, in anticipation of their eventual reunion. She would meet him after a break with her mother or just a shower and still that little flip. Rose wanted to believe it was there too for him but it just never seemed to be the right time to spill her guts, so to speak.

Rounding the corner, Rose was met with a softly illuminated console room but no Doctor.

She was faintly disappointed.

The center of the console moved steadily, though ever so slightly, up and down, as if on a stable breathing cycle. Soft turquoise light was cast about on the coral walls so that if inspected closely, seemed to set alight the entire room. It was all very calming.

Maybe he was in the library. Rose left the console room and moved back into the Tardis.

Nothing is more relaxing than good evening read, Rose Tyler! He had given her that winning smile as he exclaimed this. The one that made her usual stomach flip turn into a double-triple-somersault. And in her head, Rose whole heartedly agreed. But when she then thought of having to even show him the cover of her latest novel, her cheeks tinged a gentle pink, and she declined the unspoken offer. She casually told him she was tired and that she'd rather get her beauty rest. He sent her off with a joke and a wink, and the smallest trace of a break in a his usual character that Rose was unsure she had actually even seen.

Upon entering the cavernous library that Rose could hardly believe actually existed in such a compact little blue box, she was met with nothing but books.

She moved further into the darkened library, through the stacks filled with books, bottles, and curios scattered here and there. There was just enough light as not to trip, but not so much that anyone could actually read by. Her eyes were drawn to the ceiling and the skylight up above. A beautiful moon, full and bright, peaked through fluffy translucent clouds. It cast soft glow that seemed to mute all the colors of entire library. Perhaps being in such a large and dark space might seem imposing to another person but this was her Doctor's library in her Doctor's ship. Such a place seemed calming in this air and at this time.

Again Rose turned and left in search of the Doctor.

Walking even further into the Tardis, Rose began to realize that there was silence. Wherever the Doctor was, he brought his energy, his fidgitiness, his inability to shut down. The one time Rose had ever actually seen the Doctor sleep, he was in his regenerative coma. He had went to sleep and Rose had taken care of him. Even then, she could hear his low breathing and his sighs. It was not unlike the soft hum of the Tardis that currently permeated the halls. Rose didn't know if the Tardis actually slept or not. A space ship wouldn't be beholden to a silly day and night cycle that most lifeforms observed but the Doctor has always made it clear that the Tardis is more extraordinary than ordinary. Maybe extraordinary ships needed rest too.

A turn, a curve, then a corner. Rose wasn't exactly sure where she was or where she was going to find the Doctor. The humming breaths of the Tardis and the knowledge that the Doctor would always find her in the end, kept her going.

It was then that she came upon a door that was just the slightest bit ajar.

Curious that she should walk past several doors but this one, the one that looked like every other door, was the one that seemed to speak to her.

She tested it. The door swung open with the smallest whisper to reveal a modest room. The room had a magical sky very much like the one through the skylight in the library. This beautiful illusion showed a night sky of fluffy clouds and delicate moon that gave the room an ethereal glow. Rose was positive the Doctor could give her a complete breakdown of the technology that was used to create the effect but she wasn't much interested in asking.

A large wardrobe and a king sized four-poster bed were the largest objects in the room. Her eyes immediately found the most important part of this new room and her stomach did a little flip.

There in the center of the bed was the Doctor, her Doctor.

Moving in closer and careful to keep silent, Rose observed his sleeping form. His body was turned into the bed, left arm and leg thrown over towards the edge of the bed. The familiar tangle of sheets around his lower body indicated that the night was a just the smallest bit too warm for him as well.

Rose walked closer to the bed, nearly touching the edge of it with her thighs.

His blue undershirt seemed to have ridden up his back as he slept to reveal a healthy strip of his lower back. His head right arm was tucked beneath his torso.

Entranced, Rose moved up against the bed and leaned over for a better look.

He was breathing in and out, in and out, in and out. His lips were parted just enough to allow his lungs their freedom. This chestnut hair, free of gel, looked so soft and feathery in the fake moon light. Every freckle seemed defined against his pale skin.

The Doctor slept and Rose was absolutely breathless. His brow was free was worry. His body was relaxed. Not an ounce of stress seemed to flow through his veins. The calmness of this room and her Doctor in it nearly moved her to tears.

Perhaps this was what night time really was on the Tardis. In this world, the Doctor was the sun and the moon. Even the Tardis seemed to shut down and rest along side him. When he was awake, things were lively and constantly moving. Never a dull moment. And in the small in between bits when his body couldn't take the stress anymore, he let go and succumbed to the same sandman as everyone else.

Carefully she brought her hand up and lightly brushed her fingertips through his hair, marvelling at how soft it felt against her fingers.

She moved her hand away to see one eye staring straight up at her.