"I don't understand!" He shouts and slaps the console of the second Tardis with a rag and then aims his Sonic at it and growls in frustration. Beneath them, Elliot is tinkering with the controls, trying to use what he's learned of his father's Tardis on his own, but she won't even wake. She simply stands still as they argue over what could possibly have gone wrong.

And Clara stands against the console, feeling somewhat useless. It's her fiftieth birthday and they'd hoped to take Elliot's Tardis on its maiden voyage, but she was dead in the water – and Clara was absolutely sure the machine was dead. It wasn't humming or churning or pulsing or chiding the way the Doctor's Tardis did. With a thought, she walks calmly out through one bright and new police box and into the aged one across from it.

"Why won't she fly?" She asks as she holds the railing and climbs towards the center. "I know you can hear me, why won't my son's Tardis fly? Why won't she wake? Why is she dead?"

An image flickers at her side and she turns quickly to see herself. Herself as she'd looked the day she first stepped inside the Tardis, mug of tea still settled in her hand. The Tardis tilts her head slightly and asks, "Why am I alive?"

Clara considers the question. She'd never considered the question. What makes a Tardis live? And then a glow slips out from the crevices and illuminates the room and Clara knows the story, tells her excitedly, "You have a soul! The soul and the heart of the Tardis!" Then she shakes her head, "But why doesn't the other?"

"You gave birth to a son; I created a machine."

"It needs a soul," Clara surmises to a short nod. "Well, how do we get one?"

The Tardis stares at her. Curious look on her face as she tells her, "You've absorbed a lifetime of radiation from the Tardis, more than any other human ever has, more than any human should be capable of. Lifetimes upon lifetimes worth, stored in your cells. Enough to take an aging Tardis to Trenzalore."

Her heart is still a moment as she considers what her holographic self is saying before giving a simple and determined, "How?"

"No, Clara," comes the response from the door and she looks over to see the Doctor entering, pained expression wrinkling his features.

"Doctor, let's be honest here," she touches her hands together, and gives a small laugh, "As much as I know you need someone by your side, you need someone younger."

"You're not old," he tells her quietly.

She laughs again at him, "Don't know if you've noticed, Doctor, but we're visiting those healing waters on Volaraxium a lot more often lately."

He looks away before shaking his head. "Elliot will just stay with us. He doesn't need a Tardis – he can be our companion."

Clara nods and turns back to the Tardis, leaning against the console. "I'll be with him," she tells her.

"You won't be able to see," the Doctor says sternly, making his way towards her. "You'll be able to hear, you'll be able to help, you'll be conscious of all of the time passing. You'll understand what's happening everywhere on the ship and you'll know everything that happens in the Tardis. Every new companion, every person cared for and every person that leaves, you'll feel it."

"Good." She looks to him with a sad smile. "I won't go to Elliot's Tardis, Doctor," she pats the metal and coral fragments underneath her fingers, "I'd be right here, with you. Right until the end."

He manages an amused grin that's tainted with sorrow. "You've already sacrificed so much for me, Clara. You've already been with me – from Gallifrey to Trenzalore."

"And I would do it a million times over if it means your happiness - my son's happiness." She shakes her head and huffs a laugh, "I thought you understood that."

He swallows hard and looks up at the Tardis and then over at the hologram that stands beside Clara. "Is it possible?" Then he laments as the hologram nods sadly, "It is possible. Why wouldn't it be," he smiles at her, "My Clara; my impossible girl."

She watches him clench his jaw, eyes watering as he refuses to look back at her. Oh how he hates a goodbye, she thinks to herself, but she knows it won't be. Somewhere inside she knows this is simply a new beginning – just as her son had told her, and just as her son had told her, she'd remain the heart and the center of this incredibly brilliant and ridiculous man's world. Just in a different way, a way that might occasionally pain her and occasionally drive her mad, but she would be there.

"One more impossible task," she tells him, catching his eye and he wipes at her tears as he stops fighting his own, letting them drop over his cheeks as she raises her hands to catch them. "One more impossible run," she adds as the door to the Tardis opens again and Elliot looks up at them.

The lights of the Tardis go dim and Clara feels an odd sensation in her chest as her hologram disappears and her skin starts to glow. She turns to see the young man who rushes towards her, eyes wide with fear and she raises a golden hand to him to stop him as the Doctor steps away.

"Doctor, we promised each other forever," she smiles, "It was never going to be what we wanted, but it is what it was and you know? It was pretty awesome," she laughs then, remembering that first time he asked her where she wanted to go.

"Mum," Elliot manages, looking between his parents, trying to reconcile what was happening, but his mind is as quick as his fathers and he looks back to the doors that have snapped open, and shakes his head, "No, mum, no – I don't need..."

But the soul of the Tardis spills out around him, through him, and through the open doors in a flood of streaking stardust and it envelops the second Tardis, invading every molecule of its existence before it booms to life, the light at its top shining out into the darkening skies. Elliot watches it, but he turns back and sees the fading physicality of his mother in front of him.

"It's alright, Elliot," she nods, watching as he cries and knowing she can no longer comfort him. It seems only fitting, and entirely unfair, that she's the first woman to both fill and break his hearts. "You were the best thing I ever did, the most important boy in all of the universe – the product of a promise of love." She smiles as he nods, inhaling raggedly as his knees go weak and he falls to watch her disappearing. "You find someone good and you take her to the stars. You run and you fight, bravely and honestly and carefully, and you remember to check in on me and your father every once in a while – for as long as you can."

He moves to her, raising a hand to touch hers, but when he does, she scatters with a quick gasp, flowing upwards in a twirling vortex that spirals its way into the Tardis around them and she slowly comes to life within the machine. Clara can see her life flowing through her mind like the broken reels of an old projector. She can see with a clarity she'd never had her childhood, her mother's laughter and her father's silly faces to amuse her and she can see the children she cared for, growing before her eyes. She sees the Doctor in her youth and she sees him again on the swings and again at her mother's grave. She sees him at her front door the first time with his monk robes and his disheveled hair.

Exhaling the last breath in her lungs, Clara lives her life with him in the span of a second that lasts twenty five years. The flirtatious adventures, the times he showed off and the times she called him on his stupidity. The first kiss and the moment they stopped holding back and started to love without boundaries. She sees the moments he laid at her side with a hand at her belly and the days he rocked their son as she slept. Clara relives Elliot's first steps and his first words and the way he cried when he needed to be comforted and the way he laughed when his father told him stories.

She closes her eyes to the reality of the world around her and succumbs to the world where there is no vision, only emotion. She feels his small bony arms wrap around her body when he was frightened of a monster the Doctor had yet to destroy and she feels the palm, so easily at her cheek, as it caressed her regularly to soothe her. Clara feels the love in her for them and she pours it out into the mechanics she now possesses. She flows through it and she finds the two men still standing at the console and she sighs with relief.

The colors on the walls are like the leaves of fall and the Doctor smiles as he cries, watching them dance and he feels Elliot at his side, grasping at his legs, and he drops beside him, pulls him closer to hug him tightly.

"Your mother and I," the Doctor whispers with a laugh and a million memories float through his mind. Her laughter and her tears and the odd little giggle he cherished so. Her pout and her dimpled grin and her mangled soufflés. He looks up at the pumpkin orange that settles itself and the quiet in the console room, the calm that she brings to it and he simply laughs.

End. (Thank you for reading!)