"The Solorith must really be getting desperate," said the Doctor as he and Klára walked side-by-side down the street, now in search of a Solorith rather than running from them. Their eyes scanned every open window and door for a sign of glowing yellow skin. "They shouldn't have attacked me; it's completely against their instincts."

"They weren't attacking you," huffed Klára suddenly, staring determinedly down at the sidewalk. "Haven't you noticed? They've never been reaching for you."

"But they keep—" he began impatiently, but his legs suddenly stopped moving as realization hit him like a ton of bricks. "Oh. Oh, Klára…"

"Don't worry about it," the girl said firmly, trying to continue walking, but the Doctor took her elbow in his hand and stopped her.

"Of course I should worry, I should worry about my sanity if I didn't notice sooner," he said softly, staring into her stiffly-set face while she looked at her trainers. "You're the one they've been aiming for all this time. I'm so, so sorry, you poor child."

"I turned 18 two weeks ago, I'm not a child."

"Where are your parents, Klára?" the Doctor soldiered on with no regard for her insistence that her loneliness was nothing to worry about. "Why was no one looking after you when you were in the street crying? Why was there no one to make you wear a coat in the cold and rain?"

"They died," she snapped sharply, turning her steely eyes challengingly up to his. "We got into a fight; I ran into the road and they got hit by the car trying to avoid me. It was a long time ago."

She crossed her arms so tightly together that it seemed she was trying to tie herself into knots, curling up into herself as she bowed her head back down to her trainers. The Doctor put his hands on her trembling shoulders, feeling such a sudden tenderness toward this kindred spirit that it took the breath right out of his chest. He hugged her again, though not as tightly as before. They were still wet and cold, but this helped.

When Klára next spoke her voice was so hushed the Doctor could barely make out her words, but he knew what they were regardless. "I may be alone, but I don't want to die. There's still so much I have to do with my life."

He pressed his cheek to the top of her head. "I know," he said gently. "I know, and you won't. I promise."

Klára pulled away from him, smiling faintly and wiping at her eyes. "Don't you dare promise that," she laughed weakly. "Maybe we should split up or something, to find them faster. What exactly should I say if I come across one?"

The Doctor sternly shook his head and pulled one arm around her. This almost felt like being with Jenny again, her eagerness and warmth. "We're staying together. Keep your bottle out."

"Right."

Klára took off walking stiffly, avoiding his eyes like the plague but not so sad as before, pulling out of his arm and bounding a few steps ahead as they rounded another turn of the twisting city; as the Doctor came round behind he heard her choked cry of, "Doctor, don't-!" as the waiting Solorith's pointed tentacle-fingers burrowed straight through her chest and began to drain her blood onto the pavement.

"No," he gasped, frozen with shock. "No, no, NO! Don't you dare!" He pulled from his makeshift holster one of the spray guns and shot a jet of water at the monster's long arm, which blackened, died, and fell off. Hissing with pain for which the Doctor felt no sympathy, the Solorith dropped Klára's shuddering body to the concrete and fled. The Doctor slumped to his knees beside the girl and picked her up off the hard ground. "Klára? Klára, look at me, stay with me!"

Spilling more of her lifeblood by the second and struggling for even one proper breath, Klára turned her terrified, bulging eyes up to his. "I-…I-…"

"Shh," hushed the Doctor, cradling Klára against his chest as he recalled her woes of I may be alone, but I don't want to die as his hearts pounded painfully in his ears. "You're going to be alright, Klára, you're going to be fine." He pressed his forehead to hers and squeezed his eyes shut, remembering how he had used 10 years of his last body's lifespan to bring the dead TARDIS back from its grave.

He could not lose another one. In his timeline, Amy had died only a matter of hours ago. He'd known from the moment Klára asked "and will you tell me stories?" that she would be his next companion. She had to be. And she was so young and so full of life and promise and he could not lose her too.

Come on, he thought desperately, focusing all of his energy into stopping the flow of Klára's blood over his hands. His hearts shuddered and skipped out of sync as he pressed his open mouth to Klára's and released a flood of golden starlight, his regeneration energy, into her, draining years away from his life by the decade over and over again. The starlight filled her and emanated from her skin like a weaker regeneration; when the Doctor pulled away the blood was still hot and wet but the wound was gone, he was exhausted, and Klára was looking up at him and breathing raggedly.

"I'm alive?" she breathed out incredulously, feeling the spot in her chest where she'd been ripped open. She looked up at the Doctor, who was still holding her with his lips slightly parted with shock. He hadn't expected it to work. "You kissed me? I'm alive and you kissed me?" she gasped as though her brother had just kissed her.

The Doctor laughed and very nearly cried with the relief he felt, hugging Klára against his still very badly-fluttering chest. He had put approximately 98 years into saving her, and felt the oldest he had since his first body. He gave the right side of his chest a little thump as Klára got shakily to her feet, watching him closely. "Be grateful," he laughed weakly as Klára pulled him up, looking more worried for him than for herself despite the fact that she had been half an inch from death only moments ago. "You look even better than you did before."

"I feel better, too," grinned Klára, throwing her arms around him. "It's so weird. You're looking older, though." Her smile faltered slightly as she looked from the Doctor's significantly lighter hair, more deeply-lined face, and thinner frame, to the wounded Solorith. "What do we do with it?"

Grimly picking up the spray-bottle from where he had dropped it in his haste to look after Klára, the Doctor approached the quivering Solorith with the girl on his heels. "Solorith can't live injured," he said in a low and dangerous voice that suggested he was also trying to convince himself of what he was saying. Holding his sonic screwdriver to the bottle, he squeezed the "trigger" and sent a wide heavy jet of water at the Solorith until it crumbled, hissing its final cry, into ash onto the pavement.

The Doctor threw the bottle away from him, disgusted with what he had done and yet also cruelly pleased. "It's kinder this way."