The Doctor ran, his older knees creaking with the effort, but he didn't care, his sonic was in his hand and for the first time in some regenerations, he felt as though a gun might have been preferable, but in this instance when fighting a malevolent psychic essence, a sonic screwdriver was essentially the same thing. The creature was a curious sentience, born of the fears and dark thoughts of the good people of Whitechapel; no form, just intent and a malicious one at that. If ever there was a case of you are what you eat... he wondered if the creature had found Jack's essence as stringy as Vastra had found his flesh.

But all of his thoughts ceased into one urgent fact that dominated his being as he forced his legs faster. It was going for Clara. The destination of the thing was obvious to him now, the question as to why was also blindingly obvious... she'd let down the walls he'd so painstakingly helped her build inside her mind when she'd first emerged from his time-stream. Damn her! He felt the rage fuelled by the flood of adrenalin as panic raced through him, she was acting as bait for this monstrous creature, just like he'd promised her she would never have to.

He could imagine how she looked to the creature, a blinding beacon lit by lifetimes of fear, pain, death, the very thing to feed it's nightmare driven existence all swirling together inside one gloriously inoffensive little package. The perfect camouflage for it to continue its dark works.

The Doctor felt the air heaving through his lungs as he shouted her name, it left his lips like a raw prayer and she turned, spinning on both him and the swirling ball of plasma that was heading straight for her, her eyes widening in surprise. Then they narrowed and she set her feet, unmoving, waiting, inviting it in.

In that moment the Doctor knew with certainty what he had before only suspected; that the creature would not simply devour her nightmares, suck her soul for the darkness it could feast on inside her many many tortured lives and simply leave her the whimpering mess as it had the others. No, it would sit inside of her growing fat and repugnant, feasting until she was a hollowed out shell for however long it took. Possession was its plan.

But for all his intelligence all his scheming and planning, he wasn't fast enough. It hit her in the chest and he felt the roar of utter rage leave him as he forced his aged body to run faster, harder, run like it had never run before; his hand outstretched the sonic blasting his instructions before it was even within range in sheer desperation.

Clara crumpled and he saw the moment she was no longer herself, the moment the creature was there, it lifted her head like a puppet on a string, her beautiful face twisting into something infinitely darker as it sneered back at him. But the creature wasn't smart... vile, cruel, cunning yes, but not smart in the traditional sense. That was why it conjured a knife, wasting vital energy to coalesce the object into being, not realising it had a weapon far more potent inches from its grasp in her sonic twinned as it was, to his. The Doctor's smile was savage, he would win and then he would make it suffer.

Her usually wickedly inviting lips became simply wicked as he crashed to a halt in front of her, his sonic aimed at her chest as she looked back at him from behind her dark sinfully attractive eyes. "Watcha Doctor," the voice was hers but the accent, the tone belonged to something entirely different, the knife was in her hand, pointing at his chest just as solid now as his sonic. "Come to rescue your sweet little lass?" It's laugh was like nails on a chalk board as it stalked forward, the blade flashing and the Doctor darted back away, his clever eyes tracking the movement and finding it was manipulating her motor functions without so much as a fraction of a second delay.

"Leave her and I might consider being merciful." The Doctor bit out, certain it was not a promise he could live up to as he circled the creature, his sonic in hand as he reached behind to check on the object he had procured for this moment. Granted he hadn't expected it to be used whilst avoiding being carved up by his own Companion, but such was life.

"Oh I don't know." The creature trilled, forcing her hands to trace the outline of her body in the parody of caress, her more than appealing form clearly to its taste. "I could do things with a body like this." It licked her lips and the Doctor tried not to let his anger force him into a foolish mistake. The plan would still work, if he could just hold his temper in check. "But this mind..." the creature looked up through her lashes at him and he could see her in there, trapped behind its foulness, screaming at him. "This mind will nourish me for a long, long time. So many dark little crevices with every kind of wicked little memory buried inside, waiting for me to pull them out and play with."

The Doctor darted forward, blocking the knife he saw swing for him before it had a chance to connect, his hand went around the offending wrist and slammed it back into the wall with a crack, but the hiss of pain was all Clara and he struggled to hold fast as he shoved the sonic beneath her chin, holding her squirming and unnaturally strong form in place with his own body. There was no danger of the creature possessing him in such a way and it pained him that his Clara was so desperately fragile when it came to such attacks, perhaps more so than other humans even, his fault too of course.

"I will not tell you again." He snarled into its face, seeing only her. "Leave her now!"

The creature shifted her body against him provocatively and it might have worked save for the righteous fury that was beyond all reason coursing inside of him in this moment. "Such a pretty little thing ain't she Doctor." It darted her tongue out, delivering a long slow lick across his throat, forcing him to drive his sonic up into hers and prevent the flash of teeth he felt graze him from tearing a chunk out of his skin. The creature chuckled darkly from within her, giving it her exact sound and twisting his hearts that little bit further to know just how present she was inside of it, helpless. "Do you know how many men she will lure to their slow pitiless ends with me in control?" it taunted, it's free hand sliding down to try those same talents on him now.

The Doctor drove the sonic in further to her throat in warning, it rounded her large brown eyes on him. "You won't." It hissed certain. "If you think I'll leave her without a fight you are sorely mistaken, I'll make such a mess in here you won't be able to piece her fragile mind back together this time old man." It swore and the Doctor fought to remain resolute, "I'll claw and bite, I'll make her suffer terribly for every piece of me you unfurl." It wasn't lying, the Doctor knew that, but what choice was there.

His momentary indecision broke his concentration and the creature twisted her, breaking his hold on her wrist and attempting to wrap those small hands of hers, clawed now into talons around his throat. He reacted, a reaction he hadn't drawn on since his third face, his elbow slamming up into her face, he didn't need to see to know that her eye would bloom with bruises the next day, a smirk curled her face and it licked the blood that dripped from her damaged lip.

"So violent Doctor." It tutted at him through a smirk, "I could make her enjoy that for you, if that's what you want... In fact I'm sure one of her little other-selves did. I could introduce you two?" It sneered as the Doctor tried to wrestle her form back against the wall, pinning those talon-like hands with one of his. The sonic was in his hand again poised to act, the Doctor stared into that face, his Clara, utterly void of her now, twisted into something vile just itching to tear this world apart, to spread its malevolent reach across the globe using her as its home base. He couldn't let it. Not because he cared for the world or for this creature's sinister intents. But because he couldn't let her be the face it chose to do it in. He wouldn't lose her.

The sonic hit and the sounds she made as he clung to her, whispering his empty promises, became imprinted on his hearts like scar tissue that he knew would never leave him. He pulled the crystal ball he'd filled full of the temporal rifts own energy out of his pocket and pressed it against her chest, right over heart, drawing the creature out like venom from a wound. The force of the sonic set to the matching frequency of the rift wave after wave rippling through her, like a shepherd dog... biting at its ankles, chasing the monster onwards. But Clara was the sieve and it was filtering through her, every pore and every cell of her being, tearing and clawing just as it had promised.

Her screams echoed down the dark alley and the Doctor held her, his lips pressed to her temple, his mind against all his better judgements forcing inside, buffeting against the vile malevolence clinging on like a limpet. Every ounce of what he was, the monster he himself could be lashed at it, slashing its bonds to the memories that were giving the creature sustenance, some of the memories would never recover, he knew. But better to lose the memory of a life that wasn't hers, than her herself. The creature reached for him in desperation and the Doctor swatted it like the fly it was compared to his own malevolence, his own cruelty the horrors he had seen and the many wonders... he was a God compared to this soulless parasite and he struck at it with all the fury of one scorned.

The creature coalesced slinking from her form like the coward it was, its meal ticket stolen by the bigger, angrier monster and the Doctor curled his fist around the crystal ball feeling its essence railing within. It was out.

With care he held her body upright, her breath coming in broken choked sounds around her sobs. She was trying to be brave, trying to make sense of its monstrous intent for her, but there were memories haemorrhaging inside of her, nightmares of her own coalescing. The Doctor soothed as best he could, his presence sliding through her trying to repair the damage it had done, re-walling up memories, cauterising others that simply refused to go back. A patchwork person that's what she would be if he failed. "Clara, my Clara." He breathed, drawing out and reinforcing the memories from the 'real' her with his own shared experiences, making them the centre of her being once more.

Clara responded as only she could to his mental coaxing, she followed his lead, her gentle hands taking over where his brutish ones failed as she repaired the damage he led her to. Practice makes perfect he acknowledged as he watched her work from within her own mind they had spent so long like this right here in Victorian London not so long ago for her. He had no idea how much of that time she remembered, the days, nights, he'd spend coaxing the real her back into the light. Painstakingly relearning with her what was her and what was an Echo. He knew her mind better than he had known any others and restoring it had become a work of art to him.

"I'm ok." She whispered with her own lips, her own voice as her head dropped to his chest. So tired as he wrapped his arms around her, holding her fast the crystal ball still gripped firmly in his hand as he fought to simply not crush the thing to dust.

The Doctor relinquished her mind to her own care, drawing back so that he could see her eyes as he lifted her chin to show them to him. She blinked back tears, her right eye was swelling and darkening already, her lip was split and the sight twisted something darker in him. His face must have revealed it because her hands caught his face, forcing him to stay.

"I'm sorry." She tried to excuse it, to placate him, her face almost breaking his hearts afresh, but her reckless decision, made without him, with no thought to what it would do to him was not an act he could simply forgive. "Doctor?" Her voice broke and he didn't relent, his body stiff and unresponsive as he fought back his rage with her for what she had forced him into. But she was here and whole and the relief drove his lips against hers, he crushed her back against the wall, not caring as her body trembled still shocked by what it had experienced. He bit down on the lip he'd damaged and she hissed, bucking against him in surprise as he tasted the bitter tang of her blood against his tongue. This was what she unleashed him in. This was the beast she drove him to be.

"I'm sorry, I'm fine." Her voice was a litany against his skin as she repeated those words over and over, peppering his face with kisses. The first real ones she'd ever offered him outside of her venom induced state or his, the one she had offered whilst he sat there lamenting like a foolish old man still weakened from its effects, had been all too brief and his mind too addled to appreciate. He should have been able to welcome and savour her touch, the way her body pressed against his, her arms around his neck, her breath ghosting over his skin behind such soft lips. But his anger was too fresh, his fear too real and he shoved her away violently, clutching at his head and turning his back on her as he tried to calm himself.

"I could have lost you!" He snarled, turning at her his finger pointing accusingly, he held up the crystal ball containing the swirling essence of the creature that had so nearly made it happen.

"You didn't, I'm fine." Her hands were up placating, the tremble to them unmistakable and he glanced away knowing that her fear was not entirely just for the creature. "Doctor please look at me." She pleaded, and he couldn't deny her, he let her see the pain, the fury her actions had unleashed in him. "It had to be stopped." She tried and he darted forward, his hand going over her mouth, forcefully stopping that argument before she could voice it.

There eyes met, stone grey and golden brown, most men would submit to those eyes he realised, but then he supposed he wasn't most men and his rage was legendary. "Don't you dare." He bit out, "Don't you dare try and justify this. You could have died... or worse, been a host for this thing, its atrocities becoming yours for centuries." Tears blossomed in her eyes and he couldn't find it in him to relent. "What could possibly have been worth that risk?" he snarled leaning in close so that she could read his meaning clearly. They'd had this argument before and he hadn't bought into her ideas on it being worth the risk then and he didn't now.

She tore his hand from her mouth, her expression scathing and he braced himself. "You! That's what." She snarled the fire he so admired flaring for him now.

"I was never at risk of this thing." He declared flippantly, his estimation of her plummeting.

Clara slapped him, hard. He felt it rock his head back and he turned confused back. What had he missed? He felt his breathing quicken, she always surprised him with the force, the fury she could put behind her palm.

"You arrogant bastard!" She hissed. "You were at risk of everything. It might not have been able to possess you, but you were at risk of something far worse. Of losing yourself, your reputation, your very purpose." She turned away from him and he knew there were fresh tears sliding down her face.

"I would have caught him in the end." He bit back, affronted that she thought so little of him.

"And how many would have died?" she jabbed him in the chest. "You were too damn cautious, too afraid to risk any of us. I did what I had to make you act. To make you engage like the Doctor I know you are, I made you fix it!"

The Doctor stared back at her, her argument swirling around inside of him and settling unpleasantly. She had done this for him. Not for the people of Whitechapel, or for anything nobler. For him. It didn't sit well.

He stalked forward grabbing her by her arms. "Promise me you won't do something so foolish, ever again." He knew his grip was too tight, his expression too fierce but he couldn't school it.

Clara stared back at him, her expression a mix of sorrow and fury. "No." She snapped back. "I won't make empty promises just to make you feel better. I will always force you to confront yourself, to be the better man, or what is the point of me?"

"Stop this." He snarled, all but shaking her in his desperation to make her see sense.

"I will, when you stop needing me to." A sob broke through and her argument was so sound, so perfect that he dropped his head to hers, feeling tears in his own eyes that were born of frustration and the real fear of losing her.

"Please," he breathed, "I can't lose you, not now." It was the most honest admission he could offer and he felt her hand hesitantly go to the back of his head, her gentle hands soothing the nape of his neck her touch sending small jolts of electricity through his scalp.

"You won't." She sighed, "That's the point, if you be the man we know you are, the man I saw tonight, how can you possibly lose?"

"Clara." He drew back looking at her desperately, he wanted to explain it wasn't always that way, that sometimes he tried and lost... it was why he was the damaged creature she saw before her.

"Feeling something is not a weakness." She offered not letting him say it, "For you it has always been a strength." He found himself heartedly disagreed with that, some of his worst mistakes were born of emotion.

But he succumbed to them again, kissing her softly, his lips exploring hers, feeling her sink into his embrace as he deepened the kiss, trying to explain to her in actions what she was simply not understanding with words. "I have never been this weak before." He broke away whispering his confession into her skin, as close to the words he knew he didn't need to say to her as he thought he might ever come. "There are wounds a man can bear and those he can't. The shadow of the wound you will create haunts me."

Clara's hand brushed across his face and he felt her answering fear and her utter determination in spite of it. This was why he always chose a human Companion, they were reckless in their bravery in everything, even matters of the heart. "Living in fear of something ending is no way to live Doctor, for either of us. Everything ends you taught me that. We have to be brave enough to make the most of it in the here and now."

The Doctor released her stepping away and pocketing the crystal ball, she was right of course, but then she usually was, it didn't make it any easier. "I have told you before Clara, you expect too much of me."

Clara made to move and wobbled slightly, he caught her around the waist, placing her firmly on her feet and not relinquishing his hold on her until he got her back to the others who had been waylaid by the mess the creature had made in the Inn a few streets over. "We'll see." She promised him cryptically a determined look on her face and he found himself hoping she was right, because the way he felt right now... he couldn't imagine ever being in a position where he might be ok with risking her, let alone losing her.