Today feels like a Sunday even though there's no way to tell. At first, Rose had tried to keep track of days, held on to her calendar, but now she appreciates the elasticity of time. All she knows is that it's a day for sweatpants and no make-up, for crossword puzzles and a cup of tea. The Doctor seems to be on the same wavelength - grey t-shirt and pyjama bottoms low on his hips – when she meets him in the corridor, just outside the kitchen. She likes to think she's the one who taught him the value of lazy days.

"Good morning!"

Even his smile is lazy today, the corners of his mouth rising slowly and crinkles reaching his slightly hooded eyes. The unusual smile turns her insides to fudge all the same.

"Morning Doctor. Where are you going?" Rose asks, noticing the loaf of bread and the jam he's carrying.

"Did you know that there's a Sun room?"

Knowing the Doctor and the Tardis, Rose imagines a room so hot you can't survive in it. Maybe he'll use it to make toasts. She's reluctant to follow him to such a place but – let's be real - she'd follow him anywhere. With an old copy of the Sunday Times under her arm and a mug in her hand, she walks behind his lanky frame.

"The screen displays all the sunsets and sunrises happening around the universe right now," he explains before they reach the room, "Well, I say sun but it's not always called the sun - you humans and your simplistic terminology: the sun, the earth, the moon – what I mean is, whatever star casts light and warmth on a planet. Of course, it's not so much rising as the rotation of the planet that gives the illusion of –"

He catches the look Rose is giving him and realizes she must already know all that. They learn that kind of thing in school, 21st century humans, don't they?

Hadn't she known before entering the room that it's a screen, she would have thought that it's a window and that they had landed on a planet, such is the illusion. The light radiating from the screen is softer than she expected, as if filtering through sheer curtains, a contrast to the cool blue glow in the other areas of the ship. Displayed on the screen, are twin purple suns rising slowly over a golden lake.

"Oh! It's -" Rose snaps her fingers, trying to remember the name of the planet, "Axilo... Axilofane, yeah?"

"Yep."

They'd swam in that lake, or at least a similar one, a few days ago. The Doctor turns up a dial on the wall and she hears the faint sound of water lapping at gravel.

It's a small and cozy room with the usual coral pillars and alien knick-knacks strewn about, a sort of large bean bag faces the screen.

"Oh, I love this couch, it's brilliant," the Doctor says, collapsing on the squishy furniture.

He'd forgotten he even had it, his fifth self had bought it in a bazaar on Pluto.

Rose sits down next to him, squirming to mold the couch to her body. She rests her head on the back and her bare feet fondle the thick shaggy carpet placed underneath. A new alien sun rises over a forest of upside down trees, their roots like seaweeds reaching towards the sky to drink from the clouds. The wind ruffles the leaves, making them chime.

"It's beautiful, can we go there next?"

"Aah, Seragotax, beautiful - yes, human friendly – no! There's no oxygen and those trees would eat you up. Well, suck you to death would be more accurate."

Rose grimaces and looks back at the screen. Once the sun has completely risen over Seragotax, it changes to a new planet. It's a sunset this time, the orange light illuminating strange rock formations, like spiky arches, and flying stingrays dancing in the sky.

"What about there? Could we go?"

"Sure. Are you gonna ask that about all the planets?"

"Just the pretty ones." She grins, looking at him, and he grins back.

The Doctor takes a slice of bread out of the bag and the smell of toasts fills the room as he runs the sonic over it. He spreads a generous amount of cloudberry jam and gives it to Rose before making one for himself.

She lays the Sunday Times down on her knees and opens it to the crossword puzzle page. She tries to solve as many clues as possible by herself. Asking the Doctor feels like cheating - not that it ever stops him from "helping". She may not have her A-levels but she has good general knowledge and she's learning new things every day. She brushes a few crumbs off the paper and writes down 'cerebellum', a proud smile appearing on her lips.

Before long, the Doctor is looking over her shoulder and giving her answers to numbers she hasn't reached yet. Always one step ahead of her.

"Twelve down: Caligula."

"Stop it, you're going too fast." She nudges his ribs.

"It's teamwork, Rose. You do the ones across, I do the ones down, we help each other, we're efficient."

She rolls her eyes.

"You just want me to finish faster so we can do something else."

"Nah, I like doing this," he says.

She casts an uncertain look over his face and a tiny nod indicates that she believes him. The bean bag squishes underneath him as he changes position to rest his chin on her shoulder.

"You know this one," he says.

His breath brushes her cheek and she has to read the words twice before her brain can process them correctly.

"Ether!"

She feels him nod. They continue doing the puzzle until there are only a few empty spaces left. She could go to the library to look it up but she'd rather stay snuggled up with the Doctor. Surprisingly, he doesn't budge either. His hand rests on the newspaper, its weight on her knee.

There's a new sunset displayed on the screen, a five-point sun descending over a desert of rocks covered with cotton candy moss. She doesn't ask if they can go there, uninclined to disturb the peaceful silence.

She starts doodling on the page and his index finger follows the curvy lines she draws. It gives her an idea and she takes his hand and opens it. At first, she only traces the lines in his palm, the ballpoint pen gliding easily along the creases of his lifelines. Then, she follows the thin blue veins pulsing in his wrist. Mindful of the translucent skin, she barely presses the pen against it. From there, she maps the wiry muscles of his forearms, outlining his sinuous strength. Carefully, she turns his arm over to continue. Although, it's more difficult where there's hair, she keeps on going. A strange satisfaction comes from leaving a mark on him. A man who can change every single cell in his body, completely rewrite his DNA but submits patiently to her artistic whims.

The biro tickles and scratches him all at once and the impression lingers on his skin long after the pen has passed, leaving an inky and sensory trace. The peculiar feeling fascinates him. Therefore, when she takes his other hand and looks at him for consent, he nods. This time she starts with the back of his hand, sketching dark swirly patterns over his pale skin and connecting his freckles into constellations. She's humming a song - Yesterday maybe - seemingly unaware she's doing it. His Timelord senses are awash with pleasant sensations that make his mind tingle and his body vibrate.

While she's focused on his arm, eyes downcast, he can look at her. The suns radiate pink and orange glows across her face and cast her hair afire. Every sunset and sunrise marks a day that has passed, giving this moment an edge of eternity. Forever in a day.

"My turn," he says when his hands and forearms look like those of an old sailor.

His slender fingers wrap around her forearm, his thumb idly stroking the skin in the crook of her elbow. He taps the pen against his lower lip, eyes towards the ceiling, as he considers what to draw on her. When he begins, his writing hand is unsteady, unaccustomed to such a canvas. Nevertheless, Rose soon recognizes the circular shapes he's tracing. He's writing in Gallifreyan on her. The Doctor looks closer in concentration and the tip of his sticky-uppy hair tickles her nose. He smells like he's been rolling around in apple grass. It makes her want to nuzzle his thick brown locks.

The second set of circles he draws is more complicated, there are more shapes intertwined.

"What does it mean," she whispers when he's finished.

"It's your name and my name," he says, pointing at the corresponding symbol.

"Rose and The Doctor," she murmurs.

"Not exactly… I didn't write 'the Doctor'."

It takes Rose a moment to grasp his meaning: He wrote his real name, committed it to her skin. The implication makes her heart soar. She caresses the shapes with the tip of her finger and the Doctor shivers.

He gently takes her other arm, his leg resting along her thigh and his elbow settling on her knee for support. His face bunches up in concentration with the tip of his tongue pushing against the back of his front teeth. He starts near her elbow and leaves a string of intricate figures all the way up to her palm. Monks must have written sacred texts that way, her flesh like a delicate papyrus under his meticulous handwriting. The pen feels different inside her hand, the sensation more acute than on the rest of her skin. Her mind wanders to variations of this sensation: a paint brush on her thighs or a feather on her tummy. A tongue on her breasts. The Doctor looks up at her. The flush of her cheeks spreads to the rest of her body like a heat wave.

"Erm, so, what do these all mean?" Rose asks to dispel the tension.

The Doctor shrugs and lets got of her arm in favour of rubbing the back of his neck.

"All sorts of things."

The short answer is more revealing than any long-winded speech. She catches his eyes, something wistful in them makes her heart clench.

"We should really finish that crossword," he says, jumping off the couch. "I'll be in the library."

"Yeah… off you go."

The next day, the Doctor's arms are still covered with her scribbles.