Time isn't strictly linear.

It's something she can recall him saying. Maybe what they experienced outside those doors wasn't, but what she felt inside was. There were days of dancing and days of laughing and days of fighting and days of wonder and they were linear to her, stringing together their time outside of the box with their time inside. And time was moving faster. It moves so fast she can see the small bump in her skin long before she realizes what's happened.

Clara studies herself in a mirror. Wrings her hands through her hair and listens for the distinct noise of the Tardis landing in the yard. The smile on her face is automatic and she rushes down the stairs before she hears Angie calling out for her. The girl is giving her a curious look, but Clara ignores it. She jumps straight into his waiting arms and when he drops her back down to the ground, he tells her gleefully, "Let's watch your sun be born."

"Awesome," comes her quiet response.

"When will you be back this time?" Angie asks sternly. "Last week you weren't just gone for the day. Artie and I had to lie to dad, tell him you'd fallen ill."

"I had fallen ill," Clara asserts.

Angie nods, but the sullen look is still stuck on her face as she crosses her arms, "Hard to believe it, seein' the smug smile on your face when you got back."

"Oy!" Clara shouts, "It was not smug."

"Whatever," Angie spits, walking away.

The Doctor raises an eyebrow and watches Clara as she turns back to him. Her small nose is flared slightly and there's a touch of pink in her cheeks. He gestures to Angie, "We could, we could go another day?"

"It's Wednesday!" Clara declares. To him the next Wednesday could be five minutes from now; for her it would be in a week's time. "We can't waste the time, Doctor."

He eyes her as she moves around him and undoes the lock on the Tardis with the key she's strung around her neck. Clara pokes her head back out and watches him close the Maitland's front door behind him, looking to the ground before glancing up at her.

"I think it's time to end this," he tells her unexpectedly.

Clara's body goes numb. Wasn't it going alright? Weren't they working just fine? She takes a step back out of the Tardis and eyes him before asking, "What?"

"Meeting by appointment," he tells her. "Maybe it's time you came aboard. Full time."

She starts to smile, but it drops away as she looks back at the house, "Angie... Artie needs..."

"A mother?" The Doctor questions.

There's a nod and she feels heartbroken because she knows what he's thinking – she's not their mother and she won't ever be able to fill that role while she's with him, she wouldn't possibly be able to fill that role for them at all. Also, Angie is probably old enough to care for her younger brother for spots at a time. It's quite possible they've lost their need for her and it's equally possible she's lost her need for them – a need she hadn't realized she had.

"They've outgrown me," Clara says weakly. "Time does fly," she whispers to herself, hand falling absently at her midsection because the thought of the two children growing up makes her sick to her stomach with worry. Time flies by so rapidly and there's no way to stop it.

"You've outgrown them as well," the Doctor tells her. "It's time for your life to start, Clara."

She gives a giggle. Her life. She's twenty four. She looks up at the grin on his face and she rushes back into the Tardis, making her way to the console and looking to the buttons while she waits. The door closes behind her and she turns to see him skidding to a stop beside her, bumping her shoulder and smiling, "Birth of a sun," he repeats. "Billions of years in the past."

It's exciting and terrifying all at once, but the nausea is surprising and she suppresses it long enough for the Tardis to take its quick hop and a swing back through time and space and slow to a stop. She rushes to the front doors and holds them, looking to the Doctor for permission and he nods, making his way towards her. Clara waits anyways, knowing he's probably seen it before, but she'd rather see it with him at her side and when he's there – when his hand is laid gently against the small of her back – she pulls open the door to see the brilliant star churning in the distance.

"It's beautiful," she sighs.

"Every creation in the universe is beautiful," he smiles. "Each star, each black hole, each living being on each living planet, all unique from one another, each radiating their brilliance back out into the universe they all came from." He hugs her closer. "I never tire of creation."

Clara swallows a thought, looking back out at the bursts of molten sun and seeing the speckles of rocks and dust floating around them and she gestures, "This is our solar system – our solar system before it's our solar system."

"We could see the birth of the Earth."

"You've seen the birth of the Earth," she smiles. "I was there."

He chuckles softly and lowers himself to the ground, legs dangling over the edge of the Tardis. Clara slides down to sit next to him and she leans into him, relaxing when his arm is draped over hers. "You need to let Angie and Artie go, Clara."

"I don't want to say..."

"It wouldn't be goodbye."

She sighs, warm tears finding her cheeks. "What's happening between us? Really, Doctor. What are we doing?"

"We're exploring."

"To what end?"

They exchange a glance. He looks away first.

Clara watches the sun's surface, a vortex of swirls and pops, and she lays her head on him, closing her eyes and imagining the warmth of the rays. She could sit there for eternity with him, but she knows they have to return. They take a day to walk through the fields of dandelions on a planet whose name she can't pronounce and they take a second to visit an island in an ocean on a planet made of water where she gets sea sickness and they fight off flying sharks.

When he returns her to her doorstep though, it's only a few hours after they left and Angie is still in her room with her headphones in; Artie is playing a violent video game that she makes him stop playing to get his homework done. Clara returns to her room and she throws herself into her bed, exhausted as she kicks off her boots, crosses her feet, and stares at the ceiling.

She turns to look at the calendar, the days between today and next Wednesday. Only six more days, she tells herself with a smile and while she knows it's so much time, she also knows it'll go by in a flash. She'll be waiting at the doorstep for him soon enough. Or she could take on his offer, pushed aside in her mind, to join him full-time.

"He's gonna break your heart, you know," comes Angie's sad words from the doorway and Clara shifts, glancing up at the girl who's leaned against the door frame.

"We're talking again?" Clara surmises with a small nod of her head.

Angie enters and moves around the bed, settling onto it at her side. She contemplates her words and Clara considers just how old the girl actually is. She's not a child anymore, Clara finally acknowledges, and she waits for her to speak, knowing by the look on her face that there's something terribly important she wants to say, but also knowing that she's having doubts about telling her.

"He's a time travelling alien," Angie begins slowly, watching Clara smile. "You said he was... old, but he doesn't seem to even age." Angie looks uncomfortable, fiddling with her fingers before telling her, "What's he gonna do when you get old?"

Clara nods, watching the girl curiously because she knows that's not it. That's not the question she has for her, but she appeases her. "He'll leave me," she says firmly, then looks up at Angie, "Do you honestly think I haven't thought about it?"

"I didn't think you had," she laughs in response, calming slightly, but still unnerved.

"Angie," Clara starts, eyes finding the ceiling, "How would you feel if I resigned as your nanny?"

"I'm a bit too old for a nanny," Angie tells her honestly, "But we'd still be able to, you know, talk, right?"

Turning to look up at her, Clara smiles, "Of course we would." Sitting up, Clara touches her head, then drops her hand to her chest. She sees the concern in Angie's face and she tells her quietly, "Planet made of ocean. Flying sharks. Still a bit queasy."

Angie snorts. "Clara, you're an adult, right?"

"I'd like to think so," Clara tells her, slapping the girl's shoe lightly.

Standing, Angie tells her bluntly, but with a knowing smile, "Well, with all this time travelling, you should keep better track of time. Something tells me you're missing something and you don't even know it."

"What?" Clara breathes.

Twisting her fingers, she stands and glances at the calendar before grinning and sighing.

The girl leaves the room and Clara stares after her, considering her words and she moves to her calendar, pulling it off the wall and flipping through the months, knowing she can't really account for all the time she's actually lived. Every Wednesday is at least two to three days, so every month is at least a week longer than it should be. Clara laughs as she looks up at the doorway, wondering what on Earth the girl could be talking about and she takes a step towards the door, ready to just ask her as she fiddles with the calendar in her hands. She moves backwards in time, then forward, then back again, shaking her head slightly, and when it comes to her, Clara faints.