They go to the Middle Ages, once. She marvels at the dresses and frills and even strikes up a conversation with one of the peasants at the market. He has to drag her away; with her shouting about how the feudal system is unfair, and she can't wait for all the revolutions. He fears capsizing human history; she follows her hot head.
He tries to distract her and picks up an instrument being sold on the street. He explains it's a lute and announces he could play it in his sleep. Knowing he was waiting for her to ask, she tells him to go on and show her. She expects a concerto or something fancy, but he plucks out a few notes of Twinkle Twinkle. She laughs, and asks jokingly, "What, no Vivaldi?"
And a moment later they're peeking out a window and there's the man himself, hunched over sheet music he's penning. Maybe after they could visit the place, he thinks, see history in motion, but she only wants a taste of Italian pasta.
He pays in strange, old-fashioned money, and she can't finish the pile of spaghetti. Maybe they've been so kind and courteous to them because they're passing for a duke and duchess. They share a quick, somewhat blushing smile when they refer to her as his wife. He's made sure she's wearing clothes of the 1700s this time, and her dress made of thick red folds embroidered in gold thread in her opinion looks horrid on her, but nothing looks better in his eyes.
She's back in jeans again soon, and her eyes sparkle when it's snowing on a distant planet, only the small flecks of ice are bright purple. She smiles her bright smile and tries to catch them with her tongue. He tells her they cause horrible headaches from the toxins in the atmosphere and she shuts her mouth abruptly.
He smiles a little at the expression on her face that stays for a fleeting moment, like a guilty child caught stealing cookies. It vanishes and she drags him through streets he's seen over and over, but that somehow seem different, as if he's seeing them through her eyes.
A few hours later they're trudging in the violet slush, entirely soaked and enjoying the cold. She's wearing his long coat and he stole her scarf, so they would be even, he said.
Then she's on a beach, endlessly stretching on, mirroring the empty sky. Her hand hangs limply to one side, itching to touch his face, but scared the frail image might blow away.
And suddenly she's alone, and the cold from the snow on that faraway planet suddenly comes sharply into view in her memory, except the cold isn't biting at her numb fingers, but freezing inside her heart.
This is the story of how I died, she will think later, going over her last conversation with the Doctor. But physical dying, her heart stopping, cells dying, her body turning cold and hard and rotting away until bones are exposed would be too kind a fate. No, Rose has to keep living without the only thing she wanted. Needed.
And she's wondering whether he's found a replacement, wondering if she'll be like her, and whether he'll make the same promises to her. Wondering whether that smile really was only for Rose Tyler.