Note: This is only a crazy theory, and is most likely not going to happen in Series 6+ so this is definitely an AU. I was inspired by other stories with this, in particular x-Avarice-x's.

She was burning, and knew that she had only minutes left at the most, but everything was clear for the first time in over five decades.

Donna Temple-Noble, widower, mother and grandmother, was dying. She was old, frail and with short gray hair and looked nothing like the imposing woman that many had once known.

Months prior, she had been diagnosed with an inoperable brain tumor that would eventually kill her, but that wasn't what was bringing an end to the elderly woman's life. No, little by little her Time Lord mind was being unlocked due to her sickness, and her memories along with it. They were jumbled, out of order, and quite frankly didn't make any sense, until one day she remembered the one name that had meant everything to her.

The Doctor.

And with that, it was as if her mind caught on fire. She remembered everything, knew everything, briefly becoming the DoctorDonna once more, and her first thought was that she was going to find her Spaceman and kill him. But those thoughts quickly subsided, and she calmed down as she realized that everything he had done was out of love. She would have died that day, over fifty years ago, and her children and grandchildren would never have existed.

What was going to happen to her? Even though she had the Doctor's memories and knowledge, there was no information regarding her unique situation. She was the only one of her kind, and still human for the most part, so it was most likely that she wouldn't regenerate. But she figured that it may also be possible that she received a copy of the Doctor's remaining regenerations as well, and could possibly have three more lives coming to her... if she survived the regenerating process, that is.

Regardless, she was dying alone, which was one of her own greatest fears and only magnified by the fact that her Doctor felt much the same way, as observed in his memories. Her head was pounding as if someone was beating it like a drum, and she lowered her head into her hands. It would all be over soon.

"Donna!"

A voice had shouted to her, followed by a hand shaking her. She looked up, and found that it wasn't the Doctor who was there, but quite possibly the absolute last person she had expected.

River Song was kneeled in front of her, and placed a hand upon her shoulder. On closer inspection, Donna saw that the other woman had tears in her eyes and was looking at her with an odd combination of both pity and awe.

"River? But how, when last I saw you..."

"Hush, spoilers... you can't tell me anything, Donna. Lord only knows I've tried to get the Doctor to and he's never said much, and even locked all of the TARDIS files concerning you. I've always figured it's because you've met me in your past. But I've done some digging of my own, and did terrible things to find out what I have. Think, Donna! Why else would I be here, right before you're going to die?"

Donna tried to reply, but her pain only intensified and she couldn't form any words.

"You're a Human / Time Lord Biological Meta-Crisis. Something impossible but it still happened, because you're special. I'm so sorry for what's about to happen to you, Donna, but you're not going to be alone."

River let go of her and took several steps back, as she noticed that something was happening. Faint traces of gold energy were beginning to show on Donna's hands, and she noticed and held both out palms-first, before turning them around... wiggling her fingers all the while.

The impossible happened once again in the life of Donna Temple-Noble, however slim the odds may have been.

"It's beginning."

"What... what, I'm?"

"Yes," said River, who sniffled, "you're going to regenerate. And you're going to forget everything about who you were, and become a lost little girl... and, and I'm not going to be able to help you, not yet. I'm so sorry, Donna. But it has to be this way, or else I'll never have existed. Some day, several regenerations down the line, you will be me. This is where it all begins, this is why I had to come here... to know where I'm from."

Donna's arms, legs and head were glowing a brighter and brighter gold by the second, but she retained her consciousness long enough to speak one last time to River.

"At least... I'll be with him again some day... tell the Doctor that I forgive him, and that I love him."

"I will."

Those were the last words that Donna Temple-Noble ever heard, before being fully engulfed and consumed by the regeneration, and she was no more. River then gently placed the new now-young girl, who wore clothing several sizes too large, onto a sofa and covered her with a blanket. With each regeneration, she had lost all of her memories due to being only partially Time Lord, and didn't remember being Donna or the child... she never would. Upon her next death, whether she regenerated or not, everything that was River Song would be dead and gone.

Knowing what the girl was going to go through and what horrible things she would be used for, River felt a slight chill momentarily. She was tempted to change her own past right then and there, which would prevent so much damage and horror that was to come, but she couldn't. The Doctor knew much more about the effects of paradoxes and time than she ever would, and fully trusted his judgment in that regard.

She couldn't stay any longer, as The Silence were soon to come into the house and take the girl away for their own needs. And with a button push on her Vortex Manipulator, she was gone.