She woke up in one of the TARDIS' smaller rooms. She looked around then chuckled to herself quietly at the familiarity of this room before she began coughing. She sat up on the soft bed, jammed in the cluttered room as the Doctor entered.

The Doctor took a stethoscope from his pocket and pressed the bell to Lucy's chest. He listened but heard no heartbeat on her left side. Seeing his worried look Lucy took his hand and moved the stethoscope across to the right side of her chest and a hurried heartbeat rang through his ears.
The Doctor looked at her confused. "You're backwards." He scanned her eyes with his own.

"No," she smiled at him, "I'm not." The simple statement brought tears to his eyes though the Doctor could not explain why. Then realisation hit him. His eyes widened in disbelief.

"Timelord?"

"Timelord." She smiled at him sadly.

"What happened?"

"Little accident stopped my heart when my TARDIS died."

He listened again to her heartbeat. "Seventeen hours…?"

"Tachycardia. The heart muscle wears out after a while if we're only running on one." She laughed darkly before letting out a quiet hiss of pain. "And this isn't the first time I've seen this happen."

"It's started then?"

"Yeah."

"Who are you?"

She looked into his eyes and he just knew, "I'm thirteen, and this, Doctor, is how we die. Alone, but not truly on our own." She lay down then and drew her knees to her chest, curling into herself in pain.

"You crossed your own timeline?"

She looked up at him sitting above her, her voice a whisper. "Where was I meant to go? I didn't want to die without anyone. I needed someone to understand…" She broke off and he did understand.

A small smile appeared on her face, "You'll enjoy being ginger no doubt. Being a girl's… different too."

His face filled with mock anger, "Hey!"

"What?" Her eyes widened in surprise at his outburst.

"Spoilers." They laughed together at the little joke. A reference to the life they'd shared.

They talked about their shared memories. She tried desperately not to give any more of his future away and they laughed and remembered and talked until Lucy fell silent. The Doctor held her hand and rocked gently as he continued talking and making jokes but laughing alone now, tears beginning to sting his eyes, he clamped his eyes shut so none could escape.

Some time later Amy peered around the door. "Is she…?"

"Yeah." The Doctors voice was hoarse with unshed tears.

"Who was she?"

"She was…" He looked down at her and smiled sadly. "She was Lucy... Unlucky Thirteen… Un-Lucy." He let out a humourless laugh as the pun hit him. "The last of her kind, The Last Timelord."

"There was another?"
He looked into her eyes. Shaking his head he dropped his gaze. "No."

"So how…?"

Their eyes locked again. "She's me… from the future." Her words came to him then as tears finally spilled down his cheeks, "and this is how we die."

The Doctor layed her hand down now. Leaning down, he kissed her forehead. Amy took his hand and squeezed it gently. "Come on." She led him away from the small body curled up on the bed.

"This is how we die, never truly on our own."