Donna could see what the Doctor was about to say, and she was having none of it.
"Oh, no," she said. "Not a chance, spaceman. You aren't getting rid of me that easily." She dodged away from his outstretched hand.
"Donna, please, I'm trying to help," the Doctor said desperately.
"There's plenty of junk in here!" she said. "Look, if I just...recalibrate the thingamabob...then add this wire on top..." she dashed around, grabbing odds and ends (the Doctor winced as she ripped one particular panel out of the TARDIS), while the Doctor watched, open-mouthed.
"And finally," she said, snatching the sonic screwdriver out of the Doctor's hands, "I'll reverse the electron field around the tertiary wire." Triumphantly, she placed the strange contraption of wires and glowing pipes on top of her head, then breathed a sigh of relief. The Doctor stared, open-mouthed, for a few seconds, then finally said,
"That looks ridiculous," he said.
"It does," she said. They looked at each other, then both of them started laughing with relief.
"C'mere, you," said the Doctor, pulling Donna into a long hug.
"You're stuck with me for good now, Doctor, so don't even try getting out of it," said Donna.
"Wouldn't dream of it," said the Doctor, grinning so wide his face hurt.
"You realize you'll have to wear that for the rest of your life," said the Doctor. They were alone in the TARDIS once more. They'd said their goodbyes.
"Right. Okay. How about I take it off, let you erase my memory, then toddle off back to earth, get another temp job, and move back in with my mother. Does that sound like a better plan?"
"I-no, no it does not," the Doctor admitted.
"Good," she said. "And another thing. This thing could break, or fall off, or stop working. And if it does, you let me die. Do not erase my memories, because believe me when I say I would rather be dead." Her voice shook slightly on those last three words, and the Doctor saw that she looked more scared than angry.
"I promise," he lied.
"Good," she said, turning around. A thought struck her. She whirled back to face him again.
"You weren't even going to ask me, were you," she said.
"Oh, don't shout," he said, smiling slightly.
"This isn't funny!" she yelled. "You were going to mess with my brain without even asking me what I thought about it?" Slowly, his smile disappeared.
"I was trying to save your life," he said.
"Well, isn't that wizard!" she said. "Aren't you such a big flipping hero? You were trying to save my life, that makes it all better."
"You're being irrational," he said.
"I can't even look at you right now," she said. "Get out."
"Donna, this is my TARDIS," he pointed out.
"Not anymore, it's not!" she said, grabbing him by the arm and dragging him towards the door. "Maybe I'll leave you on earth with my mother. See what you think of it." She tossed him out.
"Donna, Donna, wait!" he yelled as the TARDIS slowly dematerialized. When it disappeared, he sat down on the grass, not sure of what to think.
An hour passed, then two, and the Doctor began to suspect that Donna wasn't coming back. Ugh, that would mean he had to stay on Earth, get a job, find a house. Become domestic. He shuddered and decided to find a nice park bench and wait a little while longer.
The next morning, he woke up with a start to the sound of the TARDIS. The door opened, and a scowling Donna appeared.
"Oh, fine," she said to the TARDIS (the Doctor felt a pang of jealousy; after all, she was his TARDIS).
"You took your time," he said to Donna. She regarded him, stony-faced, then turned her back.
"You're not still mad," he said, following after her. She ignored him and walked down one of the hallways and into her bedroom. The door slammed behind her.
"Donna, you can't keep this up forever," he yelled as he attempted to open the door. The TARDIS wasn't letting him. "Forever is a very long time!" The door remained stubbornly closed.
"A very, very long time," he muttered, finally giving up and walking away.
Knock knock knock.
"Donna," he called through the door, "we've landed on a planet completely populated by cows." No answer.
"Fine. Stay in there. Miss all the fun," he said.
Knock knock knock.
"Guess what planet I just got back from?" he said. "Come on, guess."
"The lost planet of Poosh! Beautiful cities. Lovely architecture. You would've loved it."
"We're still landed, if you want to see it."
"Your loss," he said, shrugging.
Knock knock knock.
"Donna," he coaxed, "if you come out of there, I'll let you drive the TARDIS."
That didn't work any better than anything else.
"Donna! Come quick!" the Doctor said, dashing towards her door. "Rexicorico-fallipitorious is under attack, and I need someone to help me put together a vinegar-nitrate bomb right now!" Donna opened the door.
"What's going on? Where? What d'you need me to do?" she said, panicked.
"I lied," he said. "But if you'll just let me talk to you-" He was rewarded with a string of obscenities and quite a bit of shouting before she slammed the door shut again. He smiled. He'd quite missed the shouting.
"Donna, it's been three days," he called through the door. "This is getting ridiculous. I was trying to save your life, you should be grateful-"
The door swung open, and Donna, her face red from crying, threw a high-heeled shoe at his head and slammed it again.
"Donna," he said softly, "would it help if I apologized?" Silence. Then, the door opened, just a crack.
"It would have to be a flipping fantastic apology," she said.
"There's a sun exploding, just out the door," he said. "It's really beautiful. Would you like to come out and see it?"
"All right," she said reluctantly. She opened the door.
"I see you fixed the hat," he said.
"Well, what did you think I was doing in there, crying and eating ice cream?" she said. "It's a headband now. Much more convenient."
They exited the TARDIS together and sat down on the red dust of the dwarf planet where the Doctor had landed. The sky was awash with colors, as if someone had knocked over several jars of paint. Donna gasped slightly, then turned to the Doctor expectantly, folding her arms.
"I'm sorry," the Doctor. "I didn't know this would upset you. I was only trying to save you life." Donna stared into the sky, watching the colors rocket across the universe.
"I would've been dead anyway," she said softly. "Well, I would've been alive, I suppose, but I wouldn't have been me. I would've been a...a walking corpse. Nothing left."
"Oh, that's not true," said the Doctor. "There would've been plenty left. You would've still been you. You were the most important woman in the universe before the metacrisis, you know."
"I know that," she said, waving her hand. "But I wouldn't have remembered. I'd be stuck on earth running coffee and sassing my manager and wanting to fly away but not knowing how. I really don't know if you can even try to understand what that would've been like for me."
"I could start," said the Doctor quietly. "I had to go into hiding once. Lost all my memories. Went by John Smith. I was a teacher at a boarding school. Had a maid bring me my coffee and newspaper in the morning, taught classes, filed paperwork. That sort of thing." Donna snorted.
"You?" she said. "Teaching at a boarding school? I'd pay money to see that."
"Well, you won't," said the Doctor. "Because John Smith is dead now. Pity. I rather liked him." There was a trace of lingering sadness in his voice.
"So you see it," said Donna triumphantly. "He wasn't you. He was someone else. And I don't want to be anyone else. I'm fine the way I am, thanks."
"I'm fine the way you are, too," said the Doctor. "Although the hair could use a little..." he made an incomprehensible motion with his hands.
"Well, no one asked you, spaceman," said Donna. The Doctor grinned.
"What? What is it?" she said.
"Spaceman," he said. "I like that." They sat and watched the sun explode for a while longer.
"You know what really bothers me?" said Donna. "You didn't even try. You could've fixed me. I did it easily enough. So why not?"
"Well, I'm not in the habit of cannibalizing the TARDIS whenever I need spare parts," said the Doctor. "And...I thought you'd be safer. On earth."
"Oh, smashing plan," she said sarcastically. "On earth, powerless, in London, with hordes of aliens attacking every few days."
"Anywhere's safer than with me," he said. "You saw them, Donna. My companions. I turn people into...into killing machines. Bombs waiting to go off."
"You turn them into heroes," she said. "We saved the earth, didn't we? And we could do it again, if we wanted. And look, we're all fine. Better than fine, really. We've done things most humans only dream of."
"I suppose you have," he said. "But you should know, I'm very glad things turned out the way they did. I don't want to know what would've happened if...they hadn't. The Time Lord Victorious, bouncing through space all alone, with no one to stop him." He shuddered slightly. Donna snorted.
"Time Lord Victorious," she said. "What, next are you going to declare yourself King of the Ood? You're not fooling me. You're just a spaceman with sticky-up hair and a lot of clever-looking blinky machines." He looked angry for a moment, then shook his head and smiled.
"Being a spaceman with a best mate sounds a lot better than being the Time Lord Victorious by myself," he said.
"Lucky you've got me around, then," she said. "Keep you from getting a big head. I don't know where you'd be, without me."
"Nowhere I'd like," he said. He hesitated, then said,
"If you want to go somewhere, off by yourself, I won't stop you," he said. "But I'd miss you."
"I'm not going anywhere, sunshine," said Donna. She leaned closer and put her arm around him, and they watched the stars together in silence.