You lose a new friend in Renaissance Italy; when you want to travel back to save her, the Doctor doesn't handle it well. Luckily, Donna Noble's the only sane person on this ship.
Well?"
When you turned to him, the Doctor felt a heaviness settle in his limbs. The weight of that expectant gaze, the steady surety as you waited for him to dash to the console and beginning pulling levers, twisting knobs, twisting time, back to about twenty minutes ago. Your hair was still wild from running, all tangled and frizzed. He could feel Donna watching his response, could picture her concern as she stood by the TARDIS entrance. She already knew, she'd already been where you were.
"We can't."
You were still in your sixteenth-century linen dress, so as you stared at him, trying to process his harsh tone, you looked like a painting, all soft creams and deep greens against the gold light of the TARDIS. Tragic, he thought. You looked beautiful and tragic. He hated it. Looking at you made his throat tight, so he stopped; approaching the console, eyes locked on the controls, he simply dematerialized the TARDIS into the Time Vortex.
"We... can't," you repeated. It wasn't quite a question, wasn't a statement.
"We'd be crossing our own timeline, Y/N, you know we can't do that," blunt was better, he thought. It was useless, he knew that. Knew that better than anyone, and now you'd know it. Best to be dismissive, to cut it off. "Her death is a fixed point."
You shook your head. "No."
"It is. It's fixed, there's no changing it." He steadied the TARDIS's flight path. "Might as well go and get in your normal clothes, we're not going back."
You looked desperately at Donna. Immediately, she brushed past the Doctor to join your side, rubbing your shoulder. She didn't speak, she didn't have too; Donna, in spite of the constant snark evidencing the contrary, had one of those rare abilities to just radiate unspoken empathy. It was a relief, as the Doctor glared at anything but you. You closed your eyes, and when you closed them, you saw paint and ruins and falling.
You'd stopped in early sixteenth-century Rome that morning, just one of those "See where the old girl takes us" sort of days. Wandering a marketplace, the Doctor rattling off fun(ish) facts about the Renaissance, you and Donna half-shopping, half-mimicking the Doctor behind his back. You'd met a girl there, fifteen, maybe sixteen, who worked in her family's spectacle shop in Florence and now sold the funny little glasses at a small stall here in Rome. Antonia had happily been swept up into one of your adventures; it had been chaos, but the fun kind—the Sistine chapel, you and Antonia weaponizing paint chisels, Donna attempting to play the lute. When you'd finally parted ways with Michelangelo (still majorly afraid of heights but assured that he'd painted all the figures on the ceiling himself, and that none were actually little aliens scuttling around, dropping onto passersby to steal their eyes), the four of you had chased the slippery creatures for miles, up to the top of the Colosseum.
The Doctor had been mapping out the coordinates to return the aliens to their home planet, muttering rapid mental math, when Antonia had reached into her bag and casually handed the Doctor a telescope to help his calculations. Not a spyglass, but an astronomical telescope that could properly see the stars. Working late at her father's shop, surrounded by lenses her whole life, she'd invented one from spare parts and had hoped to sell it at the market that day.
It was brilliant, far too brilliant, and far, far too early. The Doctor had said Galileo wouldn't make a telescope that powerful for another hundred years. It was then that everything had gone wrong, so quickly and painfully wrong that you still hadn't caught your breath. An alien had escaped the chest you'd secured them in, slipping out a crack in an oily, pigmented mess. As you'd talked, it trickled up Antonia's dress, sweeping down over her face in a terrible hood. You hadn't heard her scream, hadn't seen her really move. One minute she was there, beside you, all brightness and laughter, and the next, she was over the side.
