The Doctor stands at the console, one hand on the control panel. He's looking at the computer screen. Donna takes a deep breath and walks over to him.
He hasn't hit the controls to leave, even though the breach detector is threatening imminent closure. His attention is focused on the screen and the people on it.
Donna knows what all the notes on the Post-its say now. She can read and interpret the Gallifreyan symbols easily. The intricate equations for defying time and space, the reminders for milk, scribbled phone numbers for Martha and Sarah Jane and Jack. But her attention isn't on those, anymore than his is.
They're standing in the TARDIS, but they may as well be outside on Bad Wolf Bay. They stare for a moment at Rose and the Doctor in blue, wrapped up in each other's arms. Jackie is standing nearby, back turned to them and talking into her phone.
"I think they'll be happy together," the Doctor says, which is a massive understatement considering the way the two humans are desperately kissing.
"Yeah, I think so," Donna agrees cautiously. She thinks he may have had his hearts broken, but she's too afraid to ask.
The Doctor hits the controls and the TARDIS dematerializes. Donna's last glimpse of her friends is from that computer screen, as the other Doctor and Rose break apart and look in the direction where the TARDIS had been standing. Although they can't see her, she raises her hand in goodbye.
The Doctor takes a deep breath. "It's what I wanted for her," he says. "I know she didn't want to stay in one place, but this is better for her. One day she'll see that."
Donna rolls her eyes. "Yeah? You think so?"
"She chose, didn't she?" he snaps. "She chose him."
"Did you want her to choose him?" she asks cautiously, and the Doctor sighs.
"Well? Which is it?"
"If it hadn't been for him," the Doctor says thoughtfully, "I would have taken Rose and left that parallel world before Jackie knew what happened. As it is, he had to go someplace, and Rose needed someone..."
"Not someone. You. He's you and he isn't, and it may not work out between them." Even as she speaks Donna knows she is wrong. The look in the other Doctor's eye whenever he looked at Rose was unmistakable. If things don't work out, it won't be his fault.
"Anyway!" the Doctor says. "The breach between the universes is closed as of...now! Onwards and upwards, eh, Donna?" He's watching her rather more closely than he usually does, and Donna swipes at her nose to make sure there's not a smudge on it.
"Right! You know what? I thought we could try the planet Felspoon! Apparently it's got mountains that move. Can you imagine?"
"How do you know that?" the Doctor asks.
"It's in your head!" she replies cheerfully. "And if it's in your head, it's in mine!" She decides to take the controls herself - why let him have all the fun? She starts walking around the console, hitting things and bumping up levers.
"How does that feel, Donna?" The Doctor speaks slowly. "How does it feel to have it all in your head?"
"Oh, brilliant! Fantastic! Molto bene!" She beams at him.
"It's a great big universe, all packed into my brain!" Donna stares around the control room critically. "D'you know, you could fix that chameleon circuit if you really wanted to. Just try hotbinding the fragment-links and superceding the binary-" She comes to a sudden stop, her eyes widening in alarm over something.
The Doctor moves closer to her. "Donna?"
"Binary," she murmurs. "Binary, binary, binary – No! No! I'm fine."
The Doctor swallows. "Donna, listen to me –"
"My head," she whimpers, hands going to her temples. "Oh no. Oh no."
"Do you know what's happening?" he asks gently.
She closes her eyes. "Yeah."
"There's never been a human-Time Lord metacrisis before now," the Doctor says gently. "And you know why."
"Because there can't be," Donna whispers, eyes still closed. Her head hurts. Sensing the Doctor coming closer to her, she opens her eyes and jerks away from him. "I want to stay!"
"Donna. Look at me."
"I was gonna stay with you forever."
"I know." He smiles sadly. "I know you were."
"Rest of my life. Traveling in the TARDIS. The Doctor Donna. You or him, it didn't matter. I didn't care. I won't go back!"
"Donna. You know what I have to do." He sees the pain in her face and worries that time is running out.
She glares at him, anger flaring and overcoming the pain in her head. "Like hell!" And she grabs the mallet from the console and swings it at his head. He sees it coming but is so shocked that he just stands there, gaping like a fish. He goes from that to unconsciousness in seconds.
Donna tosses the mallet aside, steps over the Doctor's prone body, and starts working the controls.
"Over my dead body," she mutters, even though the pain in her head is so severe that she can barely see. She wants to lie down and cry. Maybe throw up.
She knows what she has to do. She knows what is still possible. Through the pain, she thinks of the location she needs to get to. She's just managed to program the TARDIS for that destination when the pain finally overtakes her and she passes out, landing beside the Doctor on the grated floor.
The Doctor wakes up as abruptly as he was knocked out. He's still in the TARDIS - not in the Time Vortex. Someplace else. Someplace...he starts to sit up and stops, surprised by the pain in his head. A sudden vision of Donna wielding a mallet swims into focus. Why would Donna be holding a mallet? That is completely unlike Donna. Wincing, he looks around the console room: Donna is lying on the floor. Awareness comes rushing back as he remembers the events leading to this moment.
"Donna?" He crawls over to her, afraid it's too late. "Donna!"
To his relief she stirs, groaning slightly. "Hurts," she whispers.
"Donna, look at me," the Doctor says urgently. "Look at me, Donna. Please."
She manages to open her eyes. "Ow," she whispers, and shuts them again.
"Okay, Donna, listen. I need to take out the part that's hurting. I just need-"
Donna startles him by sitting up. She crawls backwards, away from him.
"You stay away!" she snaps through the pain. "It's too late for that!"
He cannot - will not, lose another friend. "It's not too late. I can save you."
"You want to save me by killing my memories," she grits out. "No thank you." She pulls herself up and sways a bit, but damn it, she manages to stand on her own.
"Donna, you'll die!" The Doctor stands up as well, cursing the slight pain in his head.
Donna pulls the sonic screwdriver out of her trouser pocket and aims it at him. "Stay right there!"
"What - what are you doing with that?" he demands indignantly, searching through his pockets. "When did you get that?"
The pain in her head doesn't let Donna filter her thoughts. To hell with it, she decides. Enough with him getting his way all the time.
"I. Stole. It." She enunciates every word, keeping the sonic screwdriver pointed at him as she starts to shuffle to the doors of the TARDIS. "I was gonna give it to him."
"What? To him? Why?" There is no question of who "he" is, not anymore. The human Doctor has managed to leave an impression on them both that will take a long time to fade.
"Because we were gonna build a TARDIS!" she snaps. The pain is getting worse. "Build a TARDIS and run while you were busy with Rose! But then you were too chicken to say the words and she chose him. Bet you weren't counting on that, were you?"
"You were going to run away with him?" There are more urgent matters at hand, but the Doctor can't help fixating on that one.
"I know you love her!" Donna continues. "I can see inside your head! You let him have her because you were too afraid to say the words. The mighty Doctor, too afraid of three little words!"
He starts to walk to her, afraid that she will die right there and then. "Donna, please, please stand still. Let me help you."
She goes on as if she hadn't even heard him. "Well, guess what? He wasn't afraid to say them. Because I'm not! I have feelings, Doctor! And emotions! Luckily I passed those on to him, and he knew just what to say to keep Rose with him. He knows what Rose wanted to hear!"
The taunting tone in her voice can only be due to her headache, but the Doctor still doesn't know how to respond. It's as if Donna has been replaced by someone else.
"You were supposed to have Rose!" she shouts at him. "We were gonna explore. Have fun! Run for our lives. Don't worry," she adds, "we might have come to see you at Christmas."
There has simply been too much insanity happening lately. The Doctor tries to process this latest piece of information.
"And that's a mighty big might," Donna adds. "You were getting a bit too self-righteous for us, there at the end." She reaches the doors and opens them.
"Don't try to follow me!" she warns him. "Setting 3452B."
"You wouldn't!" he says indignantly.
"Ha! Wouldn't I?" And Donna disappears, being sure to seal the locks behind her.
He doesn't have a spare sonic screwdriver lying about, and it takes a few vital minutes to convince the TARDIS to open up and let him out. When the doors spring open he jumps through, looking around frantically.
Donna has passed out just steps away from the TARDIS, sprawled facedown on the floor. It's a very undignified pose, and she would hate to be seen that way. She's still alive - he can see her breathing.
The Doctor doesn't try to help her just yet. Setting 3452B is still in his mind, if he was to admit it, but that's not the reason he's not rushing to her side: a man and a woman are already kneeling over her.
The Doctor's gaze swings around the room. Recognition hits. Turning the other way, he scans the rest of the room. The person he's expecting to see is standing a few feet away, arms crossed.