I realize that there is an argument to be made for why 10 couldn't do this but I feel like its an interesting what if.
It occurred to the Doctor that he did have a solution. It was a long stretch, he didn't even know if he could do it. He wasn't sure if he even had time to do it.
But maybe just maybe he could turn Donna into a Time lord. The Doctor cupped Donna's face and looked her into the eyes. "Donna, I need you to trust me."
"What are you going to do?"
"Its a long stretch. I don't know if this is going to work."
"Doctor, what are you going to do?" Donna asked impatiently.
"I'm going to make you a Time lord. Or try to at least. I don't know how much time I have to do this. I might be able to hold it back for a while."
"You bloody well better try space man."
It wasn't easy. He had put Donna in a temporary like state, held back the threatening explosion of her head. Hooked up the TARDIS to act like a life support for her but there was only so much the old girl could do. It would be nice to have Donna use her new Time lord mind to help him but he didn't dare risk it.
Make the pocket watch turn the human into a Time Lord instead of the other way around. Donna already had some Time Lord DNA, he was the Doctor and he had saved the universe with a kettle and a piece of string. The Oncoming Storm and he had gotten up from his tinkering and kicked the TARDIS in a fit of shook from side to side and started moving.
"No! Not now! I have to save Donna!" he shouted as he tried to cling to the console. The TARDIS didn't listen. After it stopped shaking the Doctor looked at the monitor. Why out of everywhere in time and space had she brought him to a prison? He didn't have much time to consider that question before there was a knock on his door. He opened the door and looked at a familiar curly haired individual.
"Hello sweetie."
