It didn't matter how many times I tried to convince myself that he could love someone like me, I knew he never would. I was a mere human, nothing special, nothing fantastic. A man like him deserved an exotic woman from a distant planet who could match him mentally with her expertise in time travel and higher than average IQ. I couldn't deliver on any of that. I was just a mediocre, run of the mill woman from central England.

The Doctor had come into my life quite my accident. He'd been the one to pick me up from a dark place and took me to the stars – literally. Over the time we'd travelled together in the TARDIS, he'd spoke of his previous companions and all of them seemed to have something to offer. But I just couldn't see at all what had called him to take me to other worlds. Maybe I should have asked him as it was something I'd never brought myself to ask.

The last two or three days I'd tried my best to keep myself to myself while I let this confusion in my head unfold. Each day I'd retire quite early to the library or pool and so far he hadn't really noticed. He was his usual self: bouncy, child-like, but always had that all too familiar sadness sitting behind his eyes. I'd only seen him cry once, but he'd smiled through the tears, pretending that he was being silly. But, to me, he'd never be silly. He was the most amazing man I'd ever known, and I'm sure everyone else that had met him thought exactly the same. So...why would I be any different?

The TARDIS, so far, had been big enough for me to hide. But not anymore. I was sat beside the pool, listening to my own thoughts, when I heard a gentle calling of my name. And there he was, stood in the doorway. When I first met him he hadn't been the kind of man I'd have fallen for; he was boyish in his appearance with floppy hair, continuous hand gestures and a mad bowtie. Behind that and he was so much more. He was freedom, hope and a reason to live life expectantly. Since stepping on board the TARDIS, I woke up awaiting the wonder of a new world or the echoes of someone's forgotten past.

He placed a freshly brewed cup of tea and a packet of Jammie Dodgers on the table beside me. His shoes squeaked on the tiles as he spun on his heel and sat on the edge of the recliner next to me.

"You don't look dressed for swimming," he said softly, looking at my attire of jeans and blouse.

"You never know what I might have hiding under here," I laughed, looking down at my blouse, but as soon as I'd let the words fall off my lips, I realised my stupidity. I'd never been one to talk provocatively, no matter how hard I tried.

The Doctor let his expression gradually turn to a sad smile as he seemingly forgot my comment. Maybe he hadn't seen the innuendo of it.

"Why have you been avoiding me?" he asked. "I had noticed even though you always tell me I don't seem to notice anything."

I sighed and shifted awkwardly in my seat. I wanted to tell him so badly how I felt. Every time I caught sight of him and I felt the butterflies set up residence in my stomach. I'd always been so guarded when it came to men and allowing myself to fall for them. There were still old scars inside me which hadn't quite healed over completely. One of these scars was due to an old fiancée who had fallen out of love with me. He'd grown distant from me, finding more happiness in the company of others until he broke the relationship off. Maybe he hadn't been the one so to speak, but he made me feel like I fit in with everyone else. With him and I could tell everyone that someone loved me. I could be like all my old co-workers and ex-school friends who I accidentally bumped into on the street. With the Doctor...oh, it was unlike anything I'd ever felt before. Unknowingly, he'd taken me from that need to be ordinary and like everyone else, transforming me into something else. I was different now. I travelled through time and space with a mad man in a blue box. What was normal about that?

How could I just let everything spill out? I suddenly felt hot and flustered. I needed to run.

I got up from my seat quickly, ignoring his protests for me to come back. The tears began to fall down my cheeks and a lump rose in my throat.

Suddenly I felt his hand around my arm and I was turned quickly, although not forcefully.

I looked into his eyes, those deep set eyes that had become so beautiful to me. Gradually I backed up against the wall, but he stepped forward, keeping the distance between us minimal.

My heart thundered in my chest and I looked down, unable to keep eye contact. "You're playing with me," I said sternly. "Stop it!"

"Somehow I believe you're the better one at teasing," he replied. His eyes had grown darker with something I couldn't, in that moment, admit to seeing there. I just couldn't admit it to myself that he might possibly feel something for me.

Then he raised his hand and cupped my cheek, his thumb gently rubbing away the one tear that had clung there. "My dearest Sarah," he whispered. "You just don't see it. None of it. You think beauty lies in the constellations, nebulas and galaxies. But I see all of that when I look in your eyes."

"You chose me to travel with you, but why? Everyone else that you've had as a companion has had more about them..."

"Shhhh," he said, growing agitated. "There's a reason for each one of you passing through those doors. The TARDIS knows who I need, and she chose you for me, Sarah."

How could he speak to me like this when he was married to River Song? Did Time Lords have a twisted idea of marriage and then sneak off with concubines? He was confusing me, and I think he sensed that.

"Doctor, you're married to River. Why do you think I've kept away from you?" I asked, moving aside and out of the door. "How can I stand in front of the man I love day after day and know nothing can ever come of it? I age and die, you regenerate. It's as though life enjoys playing sick games with you."

I dashed down the corridor, trying to find my way back towards my room, but each and every time I attempted to get away, I kept coming back to the entrance to the pool. The Doctor stood there with his arms crossed.

"You know how the TARDIS works, Sarah. Don't keep running away. You need to face up to problems in your life rather than keep running," he told me.

"Oh, you're a fine one to say that to me seeing as you took me from home!" I shouted. "You run from your past every day, Doctor. And you stand there preaching to me about it."

I could see the frustration growing on his face and with no other words spoken he approached me quickly, and kissed me.

I tried to pull away but he had his hands on my cheeks, keeping me against him. As his lips moved, I knew I couldn't keep the running routine up. He weakened me and I stood there completely defenceless, responding to his kiss. My arms wound around his waist and I groaned beneath our locked lips.

Gradually we parted, our breaths heightened.

He smiled at me and then pressed his forehead against mine. "Never think you're unimportant. Never!"

The Doctor excused himself from my company a short time later, promising to come and see me once he'd taken care of some calculations and such in the main console room.

I took a quick swim and then had a shower, washing all of the chlorine out of my hair. But all the way through I couldn't take my mind off the Doctor. Smiles kept coming out of nowhere and I must have looked like a lunatic to anyone watching. However, I knew I needed to learn of his intentions. Where would any kind of relationship go from here? Or would it be nigh on impossible. For today I needed to forget it all and just enjoy the moment. Living in the moment for the sheer fun of it was something I'd never been able to do. My mind had always been locked on the future, stressing about the what ifs and maybes of life.

After the shower, I returned to my room only to find that the single bed which was against the wall had now turned into a double, centred amongst the simple furnishings.

What on earth was the TARDIS doing? I'd been told countless times how she needed to be sure of a person and only allowed those on board who were important and integral to the Doctor's travels. What was the reason behind my presence?

I stepped further into the room and slipped a hand down onto the crisp, white bed sheets. A tingle shot up my back making me shiver. The Doctor... and me...in this bed.

The door shut behind me and as I turned I saw him. His tweed jacket was missing and his shirt sleeves were rolled up.

"Been busy?" I asked.

"Not as busy as I'd like to be," he replied. "I think you'll make sure I have my work cut out for me."

One thing I knew was for certain: if I made love to him here, tonight, things would never be the same for me. I couldn't let this be a one night stand. My heart was his, completely. But was his heart mine?

"Doctor," I whispered. "I can't."

He smiled at me. "I know you enough by now to know why. Truth is, I know I'm married to River, but my heart...or hearts," he began. He stopped and chuckled. "My hearts aren't there. I care for River but not in the same way I care for you. In my last regeneration, I felt this way for someone else."

"Rose?" I asked. I knew it was her. Sometimes the way he spoke about her made everything so clear. She'd been his first love. He'd speak about other companions from his last regeneration like Martha and Donna, but the regret and sadness wasn't present in his voice like when he mentioned Rose. His previous companions from this regeneration, Amy and her husband, Rory, had been his best friends, sharing in so many of his trials and triumphs. Where I fit in, I didn't quite know.

"But...I'm different, Sarah. In this form I have my memories, but the feelings disappear...some of them."

"You said that you left a clone of yourself with Rose so she'd never be without you. How am I supposed to walk away from all of this without you? And I mean you as you are now."

"Isn't it better to taste love once even if it's not meant to last, than never taste it at all?" he asked me.

All reason and control left me and I leaned up to kiss him.

My hands wound up in his hair as his drifted down me, causing goose bumps to rise on my skin. I couldn't help but let out a groan, momentarily feeling embarrassment, but that soon dissipated as I found myself being disrobed.

His lips inspected me carefully, inch by inch as we made sure no more clothing could get in the way. And shortly after, we lay amongst the fresh covers. He was leaning over me, kissing my neck passionately. I'd never seen him so primal and unrestricted.

I couldn't help but arch my back as his lips travelled down my body, until he came to my inner thigh and it was then that I called out into the air.

"I don't want to wait anymore," I said, trying to get the words out coherently between the feelings which were bombarding me.

He never spoke but instead began kissing back upward, seemingly not missing an inch. And as his face came in front of mine, I took his lips back against mine but felt him enter me at the same time in one swift movement. On instinct and in shock I groaned under the kiss, and then he reciprocated.

We began to thrust against one another, matching one another's movements and as we did, he took my hands in his. I could feel the ascension to my orgasm beginning and it became so quick the harder we pulsed into one another, until finally, I felt that last turbulent wave hit me. Whilst the orgasm pulsed through me, the Doctor groaned against my neck, signalling his release.

Breathlessly, he withdrew and lay beside me.

We let our breaths come back to normal before the Doctor reached over and began tickling me. Instantly I laughed, pulling away, but he came almost on top of me, attacking me with his hands. My insides hurt as I laughed over and over, until I found a way to get at him.

I lunged forwards, still giggling and began tickling him back in retaliation. His laughter filled the room until we settled down to sleep.

I woke to find that the space next to me had become vacant and the Doctor's clothes had disappeared. Sighing, I got up, re-dressed and decided to take a walk down to the console room. Maybe he was in there, hovering over leavers and gauges...as per usual.

This time the TARDIS allowed me to walk smoothly into the console room, where I found him. I stayed by the door, watching him grinning like a happy child and hopping around the system, chattering away. Now that I'd experienced what it was like to not only travel with the Doctor, but allow him in, I knew I'd never be the same again.