1. The Time War
Top of the list of things that they Absolutely Do Not Talk About is whatever it is that the Doctor did during the Time War.
Donna isn’t even sure what a Time War is - beyond the obvious – because whenever the topic comes up he shuts down. She knows that Gallifrey burned, but that’s about it, so knowing what subjects are best avoided can be tricky. Even with what little she knows it’s a conversational minefield at times (can she talk about minefields? Did they have those in the Time War?) and her steps through it are sometimes clumsy.
Example: the unknown fate of the planet Atarfel, as discussed on Tuesday in the Vaults of Exoera:
The Doctor studied the holographic display above the ancient alien computer.
“Atarfel should be here,” he said, pointing at an empty bit of space, “but obviously it isn’t. No gravity well either. It’s just gone. So where did it go and who did it? Was it destroyed?” he wondered aloud.
“But planets are bloody huge,” said Donna, who was still fairly new to all this stuff, “you can’t just blow up an entire planet.”
The Doctor flinched, just slightly - she’d have missed it if she had blinked. Oh. Right. Yeah.
“It’s easier than you’d think,” he said, calmly enough, and then he put his glasses on to look at the star-chart, even though he hadn’t needed them a moment ago. Donna had seen this trick before – she knew that he thought the specs helped hide suddenly-moist eyes.
They didn’t, though. She touched his arm and he looked at her. “Do you want to talk about it?” she asked, gently.
“Talk about what?” He was a very good liar, that was one thing Donna had learned pretty soon after meeting him.
Gallifrey. The war. Any of that stuff. But she pointed at the display and said “Tell me how this holo-thingy works. Why does the light stop in mid-air like that?” She poked a hand into the display. “There’s no glass or anything, it should just keep going. Shouldn’t it?”
He went straight into lecture-mode, and although Donna only understood about half of what he said she let him talk at her until the specs disappeared back into his pocket and he asked, “Shall we go planet-hunting?”
“I assume it’s not just slipped down the side of the sofa.”
“That’d have to be quite a big sofa,” he said, and there was a smile at the corner of his mouth. “Come on, the sooner we start looking the sooner we find it.”
2. Her Mother
Sylvia Noble is a terrible mother, as far as the Doctor’s any judge of these things. He doesn’t mind her being rude to him (he’s faced the wrath of Jackie Tyler, and of Francine Jones, both of whom have slapped him) but he dislikes the way she undermines Donna’s confidence. Hates it, actually. Doesn’t know why Donna and Wilf put up with it. (No, he knows why, he just doesn’t understand how.) He estimates that a good 55% of Donna’s occasional self-esteem issues are related to Sylvia’s parenting skills.
Evidence: A conversation in the TARDIS greenhouse, a week ago last Thursday:
He’d shown her planets and now he was showing her plants. “The Vrokaela woodweed only blooms at night,” he told her, “and only at weekends.”
“How does it know when it’s the weekend?”
He grinned and shrugged. “No idea. Any suggestions?”
“I don’ t know much about plants. Gramps does, but he’s clever.”
He raised his eyebrows, looked at her over the tops of his glasses. “Who told you that you’re not clever?”
She shrugged. “My mum. Didn’t even expect me to pass my GCSEs.”
“But you did,” he guessed.
“Most of them.” She shook her head, looked a bit wistful. “I almost failed Maths. Passed History by one mark.” Another shrug. “We can’t all be geniuses.”
“I got 52% on the second attempt,” he admitted. “Only managed that because I spent the night before the final exam copying out my best friend’s notes. Exams don’t prove anything.”
“Yeah, but -”
“But nothing! You’re very intelligent, and you’re observant, and most importantly you’re kind.”
Donna smiled at that, and then she pulled herself up on her tiptoes and kissed his cheek. “Thanks.”
He felt himself blush, and tried to draw her attention back to the woodweed so that she wouldn’t notice. “Maybe it likes watching science-fiction on Saturday evenings, and the sport on a Sunday afternoon.”
As is his usual approach to things that hurt his friends, he places himself in harm’s way. He attracts Sylvia's xenophobic anger and bears the irritation willingly. Once Donna says “You don’t have to come to my house, you know, you can park the TARDIS in town and I’ll get the bus,” and he tells the half-truth that he likes seeing Wilf. He doesn’t say a word about her mother, in case she thinks he’s being rude about her family. Which he is, but for good reasons. The best reason, who is also his best friend.
3. His Children
Kids are sore point for both of them - her because she’s starting to think she’ll never be a mother, him because he’s not a father any more. After Messaline it’s even worse, and Donna tries to avoid the subject of children entirely until recent events have faded from his memory (if anything ever does, and she has her doubts about that).
It turns out to be almost impossible, because children are very much a fact of life. On the planet Xenefiner not only are they assumed to be married (again), but also to be parents (a first).
“Oh, we’re not -,” Donna starts to say, then stops because it’s only been a week since Jenny died. She glances at the Doctor without meaning to, and he looks away. “We’re not even married,” she explains, because that seems like the safest thing to say. This is accepted and the topic is at last dropped from the conversation, but it’s too late now and the Doctor won’t make eye contact with her.
When he does finally look at her it’s because she’s taken hold of his hand. He looks down at the connection and then manages to smile at her. He says, very lightly, “I wonder why everyone thinks we’re married.”
“People can hold hands without being married.”
“You know that, and I know that, but apparently we look like a couple. Or siblings.” He frowns. “Possibly both, in some cultures.”
“Do you want me to stop?” She loosens her grip as if to demonstrate, and he squeezes her hand in response.
“My mind wanders,” he says. “Sometimes I need a bit of an anchor, something to remind me where I actually am.”
“That’s charming,” she says, “I’m a heavy object that keeps you in your place.” She smiles to show that she doesn’t mean it.
“You do, though.” He sees her expression and hastily adds, “You’re not heavy. Not that it’d be a bad thing if you were, obviously. But you’re not. Unless you want to be heavy. Do you want to be heavy? Is that fashionable again or not?” There’s the slightest note of panic in his voice.
“Like you’d know anything about fashion.” She looks him up and down. “Pretty sure I saw Jarvis Cocker wearing that outfit in 1996.”
“1995, actually. Glastonbury.”
She pokes his arm with her free hand. “Don’t tell fibs.”
“I’m not! I had to fight off a Zygon duplicate backstage during Disco 2000!”
“Alright, I will! Come on, back to the TARDIS!”
“We’ve only just got here!”
They’re still holding hands, and she is tugged along beside him as he sets off back to the TARDIS. They’re just running away again, she knows that, but she can’t deny that it’s fun. No wonder he never stays still.
4. What Happened in the Library
The console room - three hours after they leave the Library.
They have plenty to talk about and nothing that they want to say. Donna sits on the crash-seat trying to read a magazine, and the Doctor pretends that the temporal regulator needs a bit of maintenance. They sit outside of space and time, loitering in the nowhen of the vortex, and don’t say a single word until Donna finally feels tired enough to sleep and says “Goodnight” and the Doctor nods silently in reply.
The kitchen - eighteen hours after they leave the Library
“We’re out of milk.”
It’s the first full sentence Donna’s said since yesterday, and the Doctor looks up with a start at the sound of her voice. “Sorry,” he says, “I was going to pick some up yesterday before..” He stops.
It’s a while before Donna responds. “It’s fine, I’ll just have coffee instead.” She adds MILK to the shopping list stuck to the door of the fridge and when she turns back round the Doctor has vanished.
London, 1965 - twenty-eight hours after they leave the Library
“All this for a pint of milk,” Donna gasps, holding on for dear life a hundred and fifty metres above the Houses of Parliament.
The Doctor, hanging beside her, exclaims, “I thought the Umorox were extinct!”
“I hope you’ve got a plan, I don’t think I can hold on much longer.”
“Don’t worry, I’ve had a really good idea.”
She turns her head to look at him. “What is it?”
“We let go of this railing.”
“Are you insane?”
“Yes, but don’t let that put you off.”
The third moon of Helus, 2273 - forty-two hours after they leave the Library.
“Madam, will you please keep control of your pet!”
“He’s not my pet, he’s my best friend!”
The orange-furred alien tuts. “Well, I assure you, you’ll be paying for any breakages!”
The Doctor laughs for the first time since River Song died.
The TV room - sixty-six hours after they leave the Library.
“Which popcorn did you make?” asks Donna, shuffling to the side.
He sits down beside her and hands her a bowl. “Sweet, like you.”
“I thought so. Can I hold your hand if I get scared?”
“Of a Disney film?”
“Uncanny valley, Donna!”
She sighs. “Yes, you can hold my hand if you get scared of the cartoon animals.”
“Thanks. You’re welcome to hold mine during any sad bits.”
“I hate the sad bits.”
“Yeah,” he says, “me too. They only put them in to make the happy bits seem happier.”
He talks to himself a lot now that he’s on his own. Sometimes he even talks to Donna, and fills in her replies from what he’ll have to remember for both of them. His imaginary Donna is as proud as the real thing and never backs away from an argument, never lets him disappoint her. She’s annoyed when he tells her he’s not taking on anyone to replace her, but he’ll talk her round eventually. It’s better to be on his own, all things considered.
Now she knows things he never told her, because she’s forgotten all the things that he really did tell her, and he never got round to telling her everything that he should have. He’s very, very good at avoiding personal questions and at lying by omission. Always has been, likely always will be.
But he talks to Donna, sometimes, and pretends that he isn’t alone.