Hi guys!! Guess who got bit by the Doctor Who bug? HARD. That's right, me. I watched 12 straight hours of the show (10th doctor) the other night, didn't sleep a wink. And I'm still gourging myself on this new addiction. So, just know I had to get this out of my system for now before working on my other stories. Don't worry, this is only a one shot. For now.

Martha Jones had had a very long day. Her family had been berating her as she tried to keep the peace for her brother's birthday party, she'd gotten to work and found herself guessing wrong at every diagnosis, and then she wound up on the moon with the galactic police and an alien that she couldn't take her eyes off of.

Yes, she'd had a really long day.

And she wasn't ready for it to end. Seeing the Doctor peeking out from behind a corner nearby, she grinned, running over to him.

"Back so soon?"

He grinned. "Well, you don't sound to disappointed about it."

She shrugged. "Not every day I get to see an alien,"

"True." He replied, nodding his head slowly. "But you did see quite a few up there." He said, jerking his eyes up for emphasis.

She smiled. "Yes, but those were either trying to kill me or trying to catalog me. You're a much more appealing alien."

He cocked his head, looking somewhat mischievous. "Am I?"

She blushed. Appealing. Where did that come from? No, screw where it came from. How'd it get out? Martha was distracted from her embarrassed thoughts when the doctor leaned in.

"Well?" He asked teasingly.

She snapped her head up, wishing she could stop blushing. "Just the physiology is all. Being a medical student it interests me to find something that looks so human……."She trailed off, her gaze lowering to his chest. "But isn't." She finished quietly, looking back up at him.

The Doctor watched her for a moment before speaking again. "Well, if you're that interested I wouldn't mind if you wanted a few more minutes with the stethoscope." His answer was completely innocent, but still it made her turn even redder.

"Oh, that's ok…..I- I left mine at the hospital and….."

She was cut off as he whipped a stethoscope of his own out of his pocket. "No time like the present."

She was frozen, trying to think of how to talk her way out of the awkward situation she'd put herself in. How could she be so stupid? Falling for something not even human on the first day she met him? "You……..have a stethoscope in your pocket?" She finally asked weakly, causing him to smile.

"I'm a doctor, what do you expect?" He held it out to her, his expression mischievous, but somehow consoling. If it was anyone else she would have been running by now. But he just emitted an aura of trust. She knew he wouldn't do anything to her. Reaching out, she took the instrument, looking around nervously just to try and shake his piercing gaze for a moment.

"You might want a place to sit." She said, still avoiding his eyes.

"Ah, how silly of me. Come on then." He said, turning quickly and heading energetically for what appeared to be an antique police phone booth.

Watching him slip inside, she paused, hesitant to follow. Maybe he couldn't be trusted. The place looked pretty darn small. His head quickly came back out, watching her eagerly.

"Come on. Haven't got all night." He paused, frowning to himself. "Well, I have. But I don't know about you. Don't be shy, it's much bigger on the inside." He said, motioning her in energetically, disappearing again.

Taking a deep breath, Martha made her way inside, gasping when the room practically exploded in space. The Doctor was lounging on some sort of cushioned desk chair with his feet propped up on a circular console. His fingertips were poised when she entered, but then he spread his arms out in a welcoming gesture.

"What d'you think of my ship?"

"This…this telephone booth is your-" She felt slightly dizzy. "Ship??"

He nodded, swinging his legs down. "Every alien's got to have a flying saucer, right?" He grinned.

"Wow, it's just so……..big…" She said, still unable to keep her eyes in one place for very long.

He chuckled.

Sucking in a breath because she knew his eyes were on her, Martha walked over to where was sitting, still somewhat distracted by the ship.

Turning her attention on the Doctor, she sat down in a chair across from him, scooting the wheels forward so she could reach him better. Slipping into a more professional mode, she slid the bell under his jacket, settling it against the left side of his chest; purely out of habit. It was truly the right that fascinated her more.

The Doctor just said straight as a rod, somehow still looking relaxed as he watched her. He didn't make a sound.

Listening intently, she shifted her stethoscope from one side of his chest to the other, timing the beats, studying the sounds. They were perfectly in sync with each other.

The Doctor smiled, enjoying the fact that he was a mystery to her.

Settling the tool around her neck, she looked up at him, her embarrassment having given way to fascination and curiosity. "Where are they, exactly." She asked, emphasizing the last word.

"What, you can't tell by the sound?" He teased.

She frowned at him. "Well, I didn't want to jump to conclusions. With two of them in there I have a hard time discerning where the sound's coming from some times." She said, folding her arms almost defensively.

He held his hands up playfully. "Alright, give it here then." He said, taking Martha's hand. Though startled at first, she relaxed and allowed him to guide her. Settling her hand over his right heart, the doctor began to explain, his voice very gentle, very patient.

"Here, just below here is where it actually lies." He said, patting her hand for emphasis. "But if you move a bit to the side, right here…" He slid her hand to the right some more, pressing it against more flexible ribs. "Here is where you can feel it the strongest." He explained.

Martha was surprised at how much of a difference the simple shift in movement made. "Are they both like that? Stronger at the sides I mean?"

He nodded, gently moving her hand to the other side as he did so. "Yup."

"Wow…" She breathed.

"What?" He chuckled, watching her curiously.

She shook her head. "Nothing, it's just- amazing." she paused for a moment, just keeping her hand in place, the Time Lord still keeping his eyes on her.

"What about your lungs?" She suddenly asked, placing her hand further up his chest, quickly putting her stethoscope back in her ears with the other hand.

The Doctor laughed. "Having fun then?" He asked, the sound echoing in her ears through the scope.

She blushed far worse than before, hastily moving her hands away. "I- I'm sorry…" she apologized, looking down.

"No. No, I'm good, you're fine." He said, still smiling, stopping her hand mid-movement. "Now, what was it you wanted to know?"

Regaining a little of her composure, Martha settled her stethoscope back in place, high enough over his hearts that they were no more than echoes behind his breathing. "Well, I was wondering, your hearts sound, and feel like they're the same size as a regular human heart- so wouldn't your lungs be a bit crowded?"

Doc shrugged. "Nah. They're shaped different, you know? Slightly smaller, but quite efficient. Got plenty of room in there."

Now thinking of something else, she moved the instrument into the dead center of his chest, listening around experimentally as she continued to quiz him. "So, are your hearts connected? Or do they run on separate circulatory systems?"

"No, they're connected." He said, keeping his voice fairly low so as to not hurt Martha's ears. "It hasn't happened to me in a very long time, but I know we can live with only one heart working. Though, I seem to remember it's exquisitely painful and weakening."

Martha grimaced slightly, still fascinated none the less. "So you have two to be more efficient then? Is that why your stamina is so incredible?"

The Doctor shrugged, not minding in the least that Martha was still experimenting with the stethoscope very gently all along his chest. Once in a great while she would use her bare hands, pausing to one side of a heart or the other- feeling the structure of his ribs as he breathed steadily.

"I do believe that has something to do with it, yes. But the big thing is regeneration."

Martha stopped mid movement, and looked at him, startled. "Regeneration?"

He nodded. "I'm a Time Lord. And us Lords of Time can regenerate our bodies if we are about to die. We don't look, sound, or even act exactly the same, but it's still us. If it weren't for the second heart, we would never be able to pull it off; the strain required is far to great for one heart to stand all on its own."

"Wow.." Martha breathed, sitting up and looking at him. "So you can't die?"

The Doctor shook his head. "Not right away. We can only regenerate 12 times in our lifespan. We can also choose to regenerate or not."

"Oh- well, how many times have you regenerated?"

"Nine times." He replied.

"Oh, so you only have three left?" She asked, trying to make her voice sound inquisitive instead of sad.

He smiled warmly. "No worries. This one's still fairly new- I'll be around for a good while yet. Already been around 903 years."

She smiled, reassured. "Alright then, you old man." She teased.

"Hey! Come on now, that's not fair." He smoothed his hair back- only serving to make it messier. "I don't look that bad."

She laughed.

"So doc, clean bill of health?" he asked cheerfully.

She nodded. "Not that I'm an expert in your species, but you sound fine to me."

"Good!! Now we can get along with time travel." He said, springing up and moving quickly around the console, flipping switches and turning knobs. "Where'd you fancy you'd like to go?"

Martha watched him in disbelief. "Wait- time travel???"

So, you like? Or no?