There was something about him. Something about that man I couldn't quite put my finger on. Maybe it was in the way he walked, his steps heavy and his shoulders sagging, as though carrying some great burden. I could see his silhouette outlined against the soft moonlight as he made his way towards me, slowly yet his path deliberate. He knew exactly where he was supposed to be that night, and knew why he had, of all places, arrived here.

It was clear he was a traveller. His clothes were worn, patched in several places, and his appearance was unkempt, almost- raggedy. He wore a simple shirt underneath a brown tweed jacket with patches on the elbows, topped off with a loud red bowtie under his collar. As I began to see his tired face in the moonlight I could see life had not been kind to him. For though he was young, his face- that poor man's face- was that of one who had seen war. I knew people like that, had seen them every day working in the hospital. The veterans, the heroes, who are fighting as hard as they can to stay in the present, for remembering is too painful.

As he made his slow journey across the park towards me, I made myself think. To think what it was that was so familiar about this man, who I was sure was a complete stranger. However I still couldn't shake the feeling that I knew him from somewhere, and looking back now I feel as though I should have realised the moment I saw him. Yet I waited, let him continue his gruelling walk, limping as he went, wanting to see him up close.

I could tell he was injured from the moment I lay eyes on him, but as he got closer I realised it was not physical injury that affected this man. For though he was broken beyond repair, no amount of modern medicine would be able to cure him. I have seen patients like that sometimes, the ones who have given up hope, often too traumatised or broken-hearted to care anymore.

He was only a matter of feet away now. I let my eyes take in every detail of this weary traveller, who had made such an effort to walk all this way. Only now am I beginning to realise what an effort that truly must have been. His head was hung, focusing on his feet and making them take the last few steps towards me, where I stood transfixed. And as he came to a stop in front of me in that empty park, two strangers who had happened to be in the same place at the same time, he lifted his head and looked into my eyes.

They were his eyes.

Those eyes I knew so well, the eyes I had fallen completely and utterly in love with. They say the eyes are the gateway to the soul and in that moment I believed it. For as I stared into this stranger's eyes I could see everything, everything that we had ever shared, everything we had done, everything we had seen. It really was the same, impossible man, after all of these years.

He opened his mouth to speak, what seemed like a herculean feat.

'Martha Jones,' he whispered, his eyes fixed on mine.

'Mr Smith,' I said smiling, remembering the first time we had met.

And for a moment as we both stood there, smiling at each other, I knew we were both thinking of the times we had shared together. I don't think they are something I could ever forget, even if I tried. And believe me, I have tried to forget the Doctor.

All of a sudden it was as though a cloud came over his face. The small ray of sunshine we had provided each other was fading, covered by a cloud, and now the storm was coming. I could see it written all over his face; the pain, the heartbreak, the incredible amount of loss that comes with being the last of your kind.

He sighed. 'Why do they always leave me?'

I knew in an instant what had happened to him. Having seen it happen first hand helps, I suppose. You can't easily forget what it feels like to be in love with someone who's grieving for another. A great writer I met once said 'a Rose by any other name would smell as sweet,' just apparently not a Rose named Martha.

'I'm so sorry, Doctor,' I say, still not knowing how to comfort him, even the second time around. He sank to the ground then, lost in his grief for a companion I am yet to know the name of.

And so we sat there until sunrise, occasionally talking, but never about the important things. Never about how he died, how the version of this man that I knew, my Doctor, was gone. The man with the floor-length coat who could pair sandshoes with a suit, and never missed a chance to spout a French catchphrase. We didn't talk about the companion he had lost, who she was and why she was gone. Instead we talked about the good old days, when Smith and Jones could have conquered the universe in that bright blue box of his, and when my life had seemed so simple.

I must have fallen asleep at some point, for when I woke up at first I could not see him. For a terrifying moment I thought it had all been a dream, a wistful dream of Martha Jones to see the Doctor one last time. But as I looked around I saw him a few yards away, scribbling on a crumpled piece of paper.

'What are you writing?' I asked him, happy just to see him and confirm that he was really here. But it became clear as he lifted his head to me that these storm clouds that plagued him had not yet passed. Every time I looked into his eyes I could see that hatred I knew he was capable of. Hatred for himself and for the universe.

'My resignation,' he replied, his voice serious.

'But you can't resign, Doctor- you don't even have a proper job,' I say, trying to keep my voice cheerful, in denial and not wanting him to say what I knew was coming next.

'I do have a job. I'm the Doctor, a hero, the saver of worlds. Only I can't go on being a hero anymore, Martha Jones. It's time I stopped running. Maybe settled down, found a place to live.'

'No, you can't! The universe needs you- Earth needs you!' I am begging with him, trying to stop him from what I know is inevitable.

'I'm done with interfering with other people's lives. I've done that enough times to know it never ends well. Running with the Doctor… it's not like a fairy-tale. All your adventures don't get wrapped up in a nice big bow so you can be back in time for tea. They died, Martha, and I thought that maybe, just maybe, if I was careful enough, it could be different this time. That maybe they would end up like you, living a normal life after I had said goodbye. But it never does quite work out the way we plan, does it?'

I sigh and look deeply into those sad, old, eyes. 'No. But I… I wouldn't have traded that time with you for anything. The adventures we shared, Doctor, they're forever in my memory. And I bet that whatever happens in the end, every life you touch, every single person, is going to remember you always.' There are tears welling up in my eyes now, and I fight them, knowing what I need to do. If this was the last time I would meet the Doctor, the man who crash-landed into my life and saved me so long ago, then it was time I returned the favour. 'Now you listen to me,' I begin, wiping my eyes, 'You need to take some time. Do what you need to do- settle down, find a place where you can think. Park that TARDIS somewhere and let her sit and collect dust. You need to do that for yourself. You can't just bound off on another adventure and run away from this one. It's unfinished, you haven't closed this chapter. But then, when you're ready, and I know you will be someday, Doctor, I want you to do something for me.'

He is listening to what I am saying, but I can tell it is painful for him. I realise that the grief he is feeling- no, not grief, guilt- is greater than what he has felt for any companion in a long time. The old Martha Jones, the Martha who left her life behind for this man, and who died inside at any mention of Rose, would have hated that he was this upset about another girl. But that's the funny thing about time- it changes you. Time can heal even the greatest of wounds, even when you thought it would be impossible. And so the strangest part, I realised, was that I no longer minded. I cared for him, yes, and I knew that I always would, but I had moved on.

'And what exactly is it I can do for you?' His voice is heavy, and I am afraid that whatever I say he may never be ready to listen.

I smile and reach out to touch his face for what I knew would be the last time. If I stared at it long enough I thought maybe I could commit it to memory, this new face I have had so little time with.

'Go and find a girl who can help you forget. Who can do the impossible, make you smile and laugh again, and make you remember why you run. Go and find an impossible girl, Doctor.'

He stared at me then, and it was as though we were really seeing each other for the first time. I knew it was time for our goodbye, only I didn't think I would have the strength to ever say it.

It was as though he sensed this, for after a moment he spun on his heel and began the long walk back across the park. It was early morning; children and their parents were beginning to appear, but the Doctor did not so much as glance their way. He was on a mission, I could tell, and while he still walked with shadows plaguing him, weighing down his every move, there was a new spring in his step. He held himself differently from just a few short hours ago, and with every fibre in my being I hoped he would carry my message with him. And I thought, as I watched this raggedy man, the same man with a new face walk away from me, that this, more than anything, was my legacy to the doctor.

I turned away from him, his figure in the distance becoming smaller and smaller. It was only a few seconds later when I heard it. That wheezing, groaning sound that brings hope wherever it goes. The sound of a madman on a never-ending adventure with a borrowed blue box. The sound of the Doctor off to conquer the universe. It was as though he was calling to me, and I could hear his reply so clearly even though he was already so far away.

'You know, Martha Jones, I think I might do just that.'