Bill had never seen anyone die until she met the Doctor. She hadn't even really known people who died, not people she really cared about and mourned for.
There was her mum, of course. But she hadn't known her mum. The person in her head who filled the mum space was a person she'd made up from photos and snippets of stories from Moira, a warm presence any real substance or shape. Her mum had a face now, a proper one with more expressions than a stilted smile, and that made her feel more real. Bill could imagine her better, thanks to the box of photos Moira had "found".
(Yeah, of course Bill knew where they came from. The Doctor was bad at hiding.)
She tried to feel sad about her mum, but it was hard. How could you mourn someone you didn't know? Bill felt sad about the things her mum hadn't been there for, she'd sometimes been angry and tearful at the unfairness of not having a mum, but it wasn't the same.
There had been the old lady round the corner who died when Bill was fifteen, but she hadn't really been a friend or anything. Moira had gone to the funeral. Bill didn't, because it was on a Wednesday and she had school and they didn't let you get out of double science even if it was for an old lady who gave you a box of Milk Tray every birthday. The Milk Tray was the only thing Bill really remembered about her.
She didn't have much experience with real grief.
There had been a girl at school. Her dad died. Bill remembered the day it happened--they'd all been in assembly...no, wait, not assembly. They'd all been in the assembly hall, but they'd been mucking about on the stage. Must have been drama. Funny the things you remember.
They'd all been mucking about and the school secretary had come in with the deputy. They'd talked to the teacher and then they'd taken Michelle away and the teacher had explained. Michelle had been out of school for a week and she never seemed the same again. Bill was scared to talk to her for ages in case she did something scary, like crying, or trying to bond because they were both in the dead parents club now.
Except Michelle never did anything and life went on and the point is, the important part, is that Bill had never really known anyone who died and she'd never seen anyone die.
She'd never expected to see someone die.
The skeletons in the garden had been different. They'd always been dead. They hadn't been alive and wearing red hats and nicking weird gadgets out of the Doctor's pocket before they became...dead.
The bloke the emojibots killed had been dead before Bill could stop it, before she even knew what was happening. She hadn't realised until after it was over.
That was the thing.
Spider had been alive and then he wasn't, and she'd seen the moment when he stopped being alive, and Bill couldn't get that out of her head.
She tried to go sleep the night she got back, but she tossed and turned for ages instead. When she finally fell asleep, she dreamed about his hand sticking up through the ice. Except it moved and Bill tried to get there, tried to pull him back, but she couldn't.
She didn't dream about the man with the ship tattoo. It had been equally awful to see him die, but he wasn't a kid with a red hat and friends. He'd been a bad guy.
Maybe that was how the Doctor moved on. Bill sat up in her bed, hating that she'd even been able to think that. Why did it make a difference that he'd been a big bad grown-up and Spider had been a (not very innocent, actually) kid?
Bill didn't want to think like that. She didn't want to become someone who could move on, lose count, watch someone die and not even blink.
There was a nasty feeling churning in her stomach and she had to get up. She got dressed in the darkness and crept out of the flat, quiet as a mouse so she didn't wake up Moira. This was something she couldn't talk out. Moira wouldn't get it.
Her feet took her without any conscious command, back to the tree outside the Doctor's office where the world first went sideways. Where Heather had...
Bill stuffed that thought back in a box. Heather wasn't dead, not really.
It was the place where everything else began, too. Where her journey in the TARDIS started.
Somehow, she wasn't surprised to see the Doctor leaning up against the tree. He didn't look surprised to see her, either.
She leaned next to him, shoulders touching but not pressing. It was cool and the sky overhead was clear. She could see the stars through the branches.
"I couldn't sleep," she said.
"It would be a bit silly to be out here if you weren't awake. You'd be sleep-walking."
Bill tried to laugh, but it was broken. "What about you? Can't you sleep?"
"Well, I don't need much sleep," the Doctor said, in the slow expansive way he had when he was trying to think up a lie on the spot and he got stuck.
"No, really, I don't!"
"You knew I'd come here, didn't you?" His silence spoke volumes. "How did you know?"
"You came back to the beginning. Everyone does, eventually, and you're wondering whether you want to keep doing this now you know about the bits that hurt. I'm right, aren't I?"
Bill ground a toe into the grass. "Your office is where everything started, technically."
"But my office has me in it, whereas out here, you can brood and get yourself tangled up in second thoughts all on your own, without someone to make you see sense."
"I'm not exactly alone."
"I know. Your cunning plan has gone wrong."
Bill thought about following that line of thought, but she suspected the Doctor was hoping to distract her down a looping chain of circular logic and she refused to let him get away with it. She stayed silent instead.
Eventually, the Doctor said, "Death is never easy to see and it never should be."
"Does it hurt less when you get used to it?"
"I try never to get used to it."
"But you said you move on."
"There's a difference between moving on and getting used to it. You have to move on if you want to prevent anyone else dying, but you should never treat it like it's a small thing. Nobody is ever so unimportant that their death is trivial."
Bill considered that thought carefully. "How do you lose count, then?"
"I've lived for two thousand years. If I remembered every death as vividly as you remember Spider's right now, I wouldn't be able to function."
It wasn't a comfortable thought, but Bill couldn't deny the logic. It made the Doctor seen less cruel and more...sad. It was a good argument against immortality. Something still bothered her, though. "How do you lose count of the people you've killed?"
"Ah." The Doctor was silent for a long time, and this time Bill was sure he wouldn't reply. She was about to tell him not to bother when he spoke, so softly she had to strain to hear the words. "There was a war. I fought in it--I led some terrible campaigns, the kind that people talk about in hushed whispers centuries later. Keeping count in a war like that is...impossible."
Bill had an image of huge ships flying through space, burning like suns and raining fire on worlds below. She shuddered.
"Did you win?"
"Nobody ever wins in a war." The Doctor made a sound that was too harsh to be called a chuckle. "But we're standing here, on your planet, so for a certain value of winning, I suppose we could call that a victory."
She puzzled that one out and decided not ask anything else about his war. Whatever had happened, it wasn't something her human brain wanted to think about.
"Can you sleep now?" the Doctor asked.
"I don't know."
"I could make you some tea."
Bill wrinkled her nose. "Isn't tea just going to wake me up?"
"I find it soothing."
"I think I'll go home, actually."
"Oh." Disappointment threaded through the Doctor's voice.
Bill pushed away from the tree and turned to face the Doctor. He was wearing his brooding face, so she smiled at him. "I'll see you tomorrow, yeah?"
The Doctor grinned. "Technically it's today."
"It's not today until after the sun comes up."
A severe look appeared on the Doctor's face, but Bill could see the smile trying to escape underneath. "I can see we're going to need to work on your temporal mathematics."
"I thought time was all relative," Bill said, and he got that irritated face he made when she abused science in front of him, which shouldn't have been as satisfying right now as it was.
As she walked home, watching the sky begin to lighten as the sun rose, she took a deep breath and realised the sick feeling in her stomach had gone. She had learned what she needed to, and she was ready for whatever was coming next.