The Doctor looked up and realized that Donna had left the room. A half-smile pulled up at one side of his mouth. She always knows. He fumbled with the seal and opened the letter. It was written in a feminine hand, but was not necessarily neat, and was obviously written in haste.

Doctor,

I know I am most likely the last person you want to hear from, but I hope that you will at least read this letter. I want to explain my actions of the past few days. The last ten years, really.

You were right. You were always right. I am the Bad Wolf.

It is odd to see that actually written. I created myself, I suppose, but it seems lifetimes ago.

As for the why of what I did as a youth- I did not have the most ideal upbringing. My father died when I was a baby, and my mother was forced to raise me on her own. We scraped by as best we could. My mother would work as a maid, washerwoman, even would style ladies' hair to make ends meet.

This is not to incite your pity, just an explanation of my previous actions.

When I was fifteen, our landlord began insisting on much higher payments. We simply could not meet them and were about to be evicted. I had a friend, a boy that I had grown up with- James Stone. He was a thief, but one that was deeply ingrained into London's underworld. He was able to provide for his family, and I was not going to resign myself to a much worse fate to make money.

I began to sneak to listen to James' transactions, as I could. I know what I was doing was wrong, but I felt less bad stealing back items that had previously been stolen. My first time was so shoddy. I am, to this day, shocked I got away with it. The more I did it, however, the easier it became. I realized I was good at it. It became a game of sorts, leaving those little messages, watching the law enforcement bungle it all each time. Not the most subtle of tactics for a thief, but I will plead the folly of youth.

Then, one day, there you were. A man asking all of the right questions.

There were times I thought you would be standing there waiting for me at the scene of my next crime, which fascinated me.

That was the reason I couldn't stay away.

Actually, that was only a small part of the reason. The real reason was because you believed in me. No one had ever seen me as more than a poor girl from one of the poorest parts of London. Your faith made me believe that I was truly capable of anything. That I was someone of value. Words could never express how much that has meant to me over the years.

What I told you was true- I did stop. I had gathered enough money to buy my mother a little house and had planned on returning to her. That day when I looked for you at my last crime, I was looking for you to say goodbye.

After I went home to my mother, I tried to follow your advice as best I could. I devoured every book I could get my hands on. I was eventually allowed to sit in on courses at Oxford. It was one of the happiest times of my life. I should have known, however, that it would come with a price.

It was there at Oxford that I had a class in planetary study with a Professor Moriarty. Though he had a nickname around the campuses that he is better-known by- the Master. He knew, Doctor. He somehow knew who I was and what I had done. I came to find that he is like a spider, a spider whose web touches every dark corner of London, of England. He wanted to use his knowledge of my past against me- he wanted me to come and work for him. I resisted as much as I could. Oh, how I tried, but he eventually resorted to threatening my mother.

The Master insisted that I do just "one little job for him." Which I am sure you have long figured out was always the Koh-I-Noor. Doctor, he knows of you. Is obsessed with you, actually. He wanted the Bad Wolf to lure you to him.

Now, as for Mr. Harkness- Jack was a patsy. He has no idea who I really am, no idea of my connection to Bad Wolf. He was told by the Master what to steal and what messages to leave. Doctor, please do not be too hard on Jack. Gwyneth had been married to a man with a penchant for gambling. He brought tremendous debt upon their heads with the wrong people. Gwyneth's husband died, but death is never enough to stop the Master. His agents began to press her for the money. Jack fell in love with her and offered to help clear her debt. He was committing these crimes to distract you all from the real target.

I was supposed to just act as a planted alibi for Jack. And I succeeded, until that night where I was out much later than anticipated.

I wouldn't have missed that moment on the steps for the world.

The Master found out and panicked. I had to steal the diamond earlier than planned. But I am afraid that even though the Master now has the diamond, I am still in danger. I know too much.

Doctor, please do not try to find me. As far as you are concerned, I may as well be in another universe.

DO NOT underestimate the Master. He never actually dirties his own hands with the criminal activities, so there is no way to even trace the theft of the Koh-I-Noor back to him. Not even with this confession. He is terrible- has eyes and ears everywhere. I will be on the run for a very long time.

The astrolabe is the only thing that I never returned. I knew that it had been stolen from its rightful Ottoman owners in the first place, and there was no way to return it to them. I want you to have it.

Destroy this letter after you finish it. Do not even let Miss Noble know. Please, do not try to go against the Master. I want you safe- my Doctor.

I hope you will one day be able to forgive me.

Rose Tyler

The Doctor fell back into the chair behind him, fist clenched around the now-crumpled letter. Donna flew back into the kitchen. "Doctor! Doctor! We must go at once! Jack Harkness is dead!

They arrived at the holding cells to see that a fellow inmate had stabbed Jack Harkness. The Doctor looked at the body of the young man as Inspector Smith explained how the killing was absolutely unprovoked. Donna tried her best to console Gwyneth.

The inspector's words began to fade into the background. The Doctor knew this was the work of the Master. The Master did not want Jack Harkness to talk- had maybe thought Jack had already divulged too much. He was horrified to think that one day it could be Rose lying before him. To never see that smile again or never see the light in her eyes… The Doctor vowed to himself, over the body of the American, that he would one day defeat the Master.

Epilogue

Wilfred Mott had just packed up his stall for the night. He blew into his cupped hands, trying his best to warm them in this unseasonably cold night. Late spring. More like early winter! He turned on to Baker St, nearing the house where his granddaughter lived above the Doctor.

As Wilf got closer, he saw something move upon the roof. It looked like a woman in black with a man's trousers on! Who could have believed! She stood, briefly silhouetted against the moon and then disappeared into the night. Wilf shook his head. Must be getting old. Women on rooftops. And in trousers, no less! No more toddy to keep you warm, Wilfred Mott. He swatted his hand in dismissal and started back towards his home.