A/N: So this is the last-ish chapter of this little story. I must tell you beforehand, I am VERY unsatisfied with this ending, for a number of reasons. So if any of you pro authors out there want to offer some advice, I'll gladly take it! :D
Also, I took some liberties with the canon here. This could be considered an AU, depending on how you look at it. Oh well, i'll just put up the flame shields and hope for the best!
Clara crouched in the grass, her gaze fixed on a herd of gazelle-like creatures. She glided forwards, carefully avoiding brushing sticks or rocks that might betray her presence. She had her sights set on one of the creatures who hobbled along, holding up one of its forelegs. Perhaps it had twisted its ankle, or stepped on a rock funny. Whatever the case, it struggled to maintain its balance as it grazed. Clara inched forwards a little more, tensed her leg muscles, and lunged. The herd scattered as she raced past, and flung herself upon the limping gazelle. She swung herself onto its back, and sank her claws and teeth into its neck. It brayed, and collapsed under her weight, rolling over and squishing Clara beneath it. The human gripped on tighter, however, as the beast's thrashing grew weaker. Finally, it lay still. Clara pushed it off her, and sat up. She had made her first kill! Instead of feeling pleased with herself, she felt a twinge of…remorse? It didn't seem natural. A faint memory flashed through her mind, of a man who abhorred violence. It made her uncomfortable, so she dismissed it. She slung the carcass over her shoulder, and started the long trek back to her horse.
Upon reaching her mount, Clara tied her catch onto the beast's back, and climbed up. She was exhausted, having met several herds before without succeeding in catching anything. She kicked her horse into a canter, thundering towards home.
-ooo-
The Master sat outside his tent, scanning the ever-darkening sky. Finally, he saw a dark shape approaching. Clara's horse loped into the camp, exhausted. Clara was almost asleep in the saddle, and she half climbed, half fell off her mount. The Master was instantly at her side, steadying her as her knees threatened to buckle.
"I did it, Master!" Clara managed. She tried to untie her catch, but fumbled with the knots, and the Master stopped her.
"I'll take care of this. You go get some sleep."
Clara tried to take a step, but her stiffened legs wouldn't support her, and she would have it her head on the stones had the Time Lord not caught her. He carried her into the tent, and laid her down, covering her with one of the soft furs.
"You have done well, my dear," He murmured, brushing a stray wisp of hair from her face. "Be proud of yourself."
-ooo-
Clara woke late the next morning. She stepped outside to see the Master sitting by a fire, with a fish cooking over it.
"Sorry I slept so late," She mumbled, plopping down next to him. The Time Lord bared his fangs in a grin.
"Don't worry about it. Solo hunters always sleep late after they've been out. They need the rest."
Clara glanced at the fire. "I didn't know you cooked your food. Don't cats like it raw?"
The Master chuckled, reaching over to turn the fish. "I may act like a cat, but I am still a Time Lord. I will eat raw if I must, but yes, I do prefer my food to be cooked. I don't think the cheetah-people quite know what to make of it."
Clara laughed, as the Master took the fish off the flames, and started shredding the scales off with his claws. He handed half the meat to Clara, and the two started eating.
Once they were done, the Master stamped out the fire and told Clara that they would train lighter since she had just hunted the day before. The two rode into the wilderness for several miles, then dismounted and practiced stalking some. The Master got distracted by a bird, and vanished into the grass. Clara stifled her laughter, and sat down to await his return.
Suddenly, she smelled something foreign. She crept to the top of the nearby ridge, sniffing the air. She smelled wood, and metal, and…something else. She tensed her leg muscles, and lunged over the top of the ridge, only to skid to a halt. A familiar blue box sat several hundred yards away, and standing in front of it was a tall gangly Scotsman. Sensing her presence, he turned, his eyes widening as he saw her. Finally, Clara managed a single strangled word.
"Doctor!"
The Time Lord seemed frozen to the spot. Clara couldn't believe how much he had changed in the few months she had been here. His hair was grayer, and his eyes had a look of hopelessness to them.
"Clara…oh Rassilon, is that you? What's happened to you?"
Clara looked down at herself, unable to respond. She had changed so much since she had arrived, yet she had only barely noticed it, taking it in stride. Now she saw the thick yellow fur coating her arms, felt the whiskers twitching to the sides of her mouth.
"The cheetah virus happened, Doctor!" A new voice called. The Doctor went stiff, a new horror showing in his eyes. Clara felt a heavy hand resting on her shoulder.
"Clara, that's the Master!" The Doctor cried urgently. "He's dangerous! Get away from him!"
Clara looked at the Master, then back to the Doctor, unsure who to trust. The Master had been kind to her from the moment she had arrived. Even when he had dragged her back to camp on her numerous escape attempts, he had probably prevented her from dying of heat, or lack of food and water. The Doctor looked like a stranger to her now, yet he still had the kindly aura that drew her in.
"Clara, the Master is using you! He needed you to get to me, even though this is the wrong time stream! It's—it's—" The Doctor paused, trying to figure out how to explain. "Soon, one of my past selves will come here, and if you stay here, it'll create a paradox! You have to come with me!"
Despite her confusion, Clara felt a familiar feeling bubbling in her chest—rage. She turned to the Master, teeth bared.
"So all this time, you were just using me to get to the Doctor? All these days and months, I thought you actually cared for me, and you were planning to just toss me aside! The Doctor was right, you're just a selfish coward who uses whomever you need, then disposes of them once they're through being useful!"
The Master's amber eyes shone with fury. His voice was a low, feral growl as he spoke.
"No one dares call me coward!"
Clara lowered herself into a fighting stance. "I dare."
She launched herself at him, bowling the Time Lord over and shredding at his face with her claws. However, her element of surprise was short-lived, as the Master had both weight and experience on his side. He flipped them over so that Clara was pinned under him, and pressed his claws to her throat. Clara froze, breathing heavily, fury still blazing in her eyes.
"Be done with it, then," She growled. "At least I can die knowing that you'll have the fury of the Oncoming Storm coming down on you."
The Master barely had time to register what her words meant, before a strong hand seized the back of his jacket, hauling him upright and hurling him hard upon the stones. The Doctor placed himself in front of Clara, eyes blazing.
"Touch my Clara again, and I'll deal with you, paradox or no paradox!" He snarled. Clara had never seen this incarnation get angry before—it was something she never wanted to see again. The Master picked himself upright, running his hand along the fine scratch marks Clara had made, grinning.
"The cheetah-virus may be loosening its grip on you, my dear," He hissed, "But it has done its work. I knew from the moment I saw you that you had leaped into the Doctor's time stream. And since the Doctor and his TARDIS are linked, the Doctor's heart is the heart of the TARDIS. That makes you, my dear, a deity described by the cheetah-people as the Bad Wolf. However, the enemy of the wolf has been in you for too long now! The TARDIS will loosen its protection on you, your past lives will catch up on you, and you will die!"
The Master lunged forwards, raking his claws across the Doctor's face, before vanishing into the grass. Clara started after him, but the Doctor held her back.
"Clara, we need to get inside right now! If every single one of your past lives converge in the TARDIS, she won't be able to handle the paradox!"
He pushed her through the door and into the time machine, then took her face in his hands. Her cheetah features had begun to fade rapidly, her brown eyes leaking tears.
"Clara, I need you to trust me." He said. "I know you've been through a lot, but you need to follow my instruction without question."
"Why? What's going to happen?" She asked. The Doctor smiled slightly.
"Now, if I told you that, I wouldn't need you to trust me."
He pressed a kiss to her forehead, before retreating to the top of the stairs.
"Now Clara, under the console, there's a grate. I need you to go and lift it up."
Clara found the grate, and after fumbling with the latch, flung it open. A white-hot glow burst forth, so bright that Clara stepped back. The TARDIS looked into her mind, and she looked into the mind of the TARDIS. Her cheetah features faded completely, leaving the brown-haired, chocolate-eyed human standing before the immense light. The Doctor ran forwards, shielding his eyes, and slammed the grate shut. The light faded, and Clara's knees buckled. The Doctor caught her, holding her close.
"How do you feel?" He asked. Clara wrapped her arms around him. Her eyes swirled with golden light, before it dissipated for good.
"Like I was run over by a bus," She mumbled. She looked up at him, and her tired gaze flickered with concern.
"Oh, Doctor, you're bleeding!"
The Doctor smiled slightly. "Don't worry about it. I'm sorry if I scared you back there, I know you were confused."
Clara buried her face into the Doctor's fuzzy vest, and let all the tears she had been holding back flow. The Time Lord sat down in the console chair, Clara in his lap, and comforted her as best he could. No more, he vowed. No more would he allow this to happen to his Impossible Girl.