"Look, just hold still, will you?" Martha said, fitting a stethoscope in her ears and pushing the man back down into a sitting position. "You might have done yourself a serious injury, but there's no point in going to a hospital if all you've done is bruised yourself."

"Oh, and I suppose you'd know, would you?" the man said, fidgeting impatiently and raising a supercilious eyebrow at her.

"Well, seeing as I'm doing a degree in medicine, I'd say yes!" Martha responded tetchily. The man pouted, looking like a sulking four-year-old. "Just let me listen to your heart."

"If you are a medical student, then tell me this," he said, with the air of someone intent on being proven right, "what's pneumonoultramicroscopicsilicovolcanoconoisis?" He raised an eyebrow at her again, an expression of smugness this time, as she stared disbelievingly at him.

"It's a disease caused by the inhalation of volcanic sediments," she intoned calmly. "Now be quiet and let me check your heart rate!"

"Look, I've told you, I'm fine," the man said, attempting to get up from the bench Martha had sat him on to check he hadn't done himself any serious damage. Perhaps he's got a concussion, she wondered idly.

"How many fingers am I holding up?" she asked, showing him four fingers.

"Eight," he replied, without missing a beat. "Where's my tie?"

"I put it on top of my bag, over there," she said. "And it's four fingers."

"You've obviously never watched 'Patch Adams'."

"What?"

"Look," he said exasperatedly, "I'm fine, you're fine, I just had a bit of a funny turn. It happens sometimes. Now can you please let me go on my way?" He grabbed his tie and started stalking quickly out of the park and towards the main road. Martha grabbed her bag and hurried after him.

"Can you at least let me check your pulse?" she said. "I just want to make sure you're alright! I'm worried!"

"Well, don't," he said, waving his tie at her. "And don't even think about following me, either." At this comment, Martha simply threw her head back and laughed. The man frowned at her obvious mirth. "Why's that so funny?"

"Psychology," she said, still chuckling. "Tell someone not to do something, and they do it. You'd've been better off just thanking me for helping you and going on your way." She narrowed her eyes at him, still smiling slightly. "Now I'm intrigued. Why won't you let me help you?"

"I don't need your help," he said, his eyes hardening. Martha absent-mindedly wondered why. He furiously redid his tie and shoved it haphazardly back into the front of his jacket.

"But who are you?" Martha asked. "What's your name?"

"What would be the point of you knowing my name?" he asked, looking genuinely confused. "What are you going to do with it? Graffiti it all over the place? Take it out for dinner? Turn it into a t-shirt slogan?"

"I'm Martha," she said suddenly, not quite knowing why. "I'm a medical student who just happened to be passing when you looked like you needed help, and now I'm starting to feel annoyed that you're brushing me away." She could feel her frustration rising and knew she shouldn't take it out on a perfect stranger, but something in her made her think that, for some reason, this man might actually listen. "It's people like you who don't appreciate the medical profession that make us feel like we're doing this for nothing, and I for one will not stand for it. I offer you help, and you turn it away without even thinking you might need it. You can't always tell what's right for you and what's wrong for you, and that," (she emphasised the word by jabbing her finger at his chest) "is what being a doctor is all about!" She narrowed her eyes at him and tried desperately to get her breathing back to normal. "Now give me a proper answer," she concluded, looking him directly in the eye. "Who are you?"

The man stared at her as if seeing her for the first time. He stared and stared, and Martha started to feel slightly self-conscious about having yelled at a stranger in the middle of the street. And still the man was staring.

"What?!" she said loudly. The man merely smiled.

"I'm the Doctor," he said quietly. Without saying another word, he opened his jacket, picked up the stethoscope that was dangling out of her bag and offered it to her. "You want to help? Ok. See if you can help." Suspicious of this 'doctor', Martha grabbed the stethoscope and fixed it in her ears again before pressing the diaphragm to his chest. As she listened to his heartbeat, she frowned slightly. She flicked the diaphragm and rubbed it a few times before putting it back on his chest.

"What do you hear?" the man – the Doctor – asked gently. Martha looked up at him, slightly confused.

"There's some sort of echo in the thoracic cavity," she said. "I can hear your heartbeat, but there's …" She frowned down at his chest again before brusquely shaking her head and putting her equipment away. "Must be a problem with the stethoscope," she said, snapping her black bag shut and slinging it over her shoulder. The Doctor smiled down at her.

"Must be," he agreed enigmatically. And without another word, he took Martha's hand and placed it on the right side of his chest.

"What are you –" Martha began, but her breath caught in her throat and her own heart nearly stopped as she felt the impossible – a second heartbeat. She stared up at the Doctor, who merely grinned smugly.

"It's not an echo," she breathed.

"Nope," he agreed.

"Two hearts."

"Yup."

"You've got two hearts."

"Yup."

Martha found she couldn't move a muscle. Her hand was clamped to this … this … thing's chest, her feet were rooted to the spot and her eyes were locked onto his. He was grinning at her warmly, as if greeting an old friend.

"It's been a while since I've let someone feel me up," the Doctor joked. Martha just blinked.

"What … are … are you some sort of …" She couldn't say it. It was ridiculous! Then again … she was standing in front of a man with two hearts. There wasn't much left that she felt wasn't ridiculous. "Are you some sort of … alien?"

"Alien?" he said, sounding insulted. "Me?" Martha nodded. "Actually, I am," he said, with a lightning-quick change of mood. "Last of the Time Lords, at your service." He stepped away from her and held out his hand for her to shake. Martha just looked dumbfounded. "It's true!" he said indignantly, before winking cheekily, shaking Martha out of her reverie and making her giggle like a schoolgirl. He flashed her another grin and she felt certain that whatever he asked her next, her answer would be a definite and resounding 'yes'.

"Want to see my spaceship?"

FIN