Anita finds Professor Song standing on a balcony that wasn't there an hour ago, staring up at the stars. In theory they should all be able to do that here-move at the speed of thought, create whole worlds on a mere whim-but the Professor's the only one who's truly mastered it so far. A game of I-Spy between her and CAL is really something to behold.

"The kids are asleep."

She catches the curve of River Song's smile, illuminated by the digital moonlight.

"That was quick."

Anita's eyes shift to the book clasped in the other woman's hands.

"Your stories tire them out."

The Professor chuckles as the world shifts around them and suddenly they're strolling amongst the stars, following the path of an asteroid belt. Anita realises that she must be getting used to this, the sudden skips and jumps in time and space. This shift hasn't caused any of the disorientation it usually does.

They wander in companionable silence for a while as Anita tries not to think about all the laws of Physics they're breaking by taking a walk through space. It's another thing about this place that never seems to bother River Song, for all that Anita knows the woman has at least two PhDs in the subject. She seems different tonight, more open, and Anita–once an archaeologist, always an archaeologist-decides to take advantage of the mood. It takes her a while to work up the nerve-she's seen the Professor shoot people for less-but finally she manages to ask.

"You loved him didn't you? The Doctor I mean?"

The Professor's pace doesn't slow, and to Anita's relief she doesn't appear to be angry, but her face falls into the same expression it always does when she talks about the Doctor, a little bit sad and a little bit happy and a little bit longing.

"Yes, I did. Do. Will."

"Time travel," she explains apologetically as Anita looks at her, confused "this language doesn't have the right tense for it, and Gallifreyan doesn't translate."

Anita nods.

"Do you ever miss it? Time travel I mean?" she's not sure why she keeps going, she was pushing her luck the first time, but Anita's always had a penchant for doing stupid things. It got her kicked out of several other universities before the Professor stood up for her and took her under her wing.

The Professor shrugs.

"We can time travel here."

Around them, everything speeds up. Rocks crash into the belt around them, nearby stars flare into supernova then blink out, black holes form then collapse. It's beautiful, and entirely not what Anita meant.

"I didn't…that's not really what I was asking. I meant… all that adventure, all that excitement, a man you loved, and now you're stuck here, where he isn't and nothing ever really happens. Doesn't it drive you mad?"

Time slows down again, and Professor Song seats herself gracefully on a nearby comet, the swinging of her feet creating eddies in the cloud of space dust that's accumulated around them. When she speaks Anita isn't really sure if the Professor is answering her, or just giving voice to her own thoughts.

"Imagine loving someone so much that you'd destroy entire galaxies for them, wipe out civilisations, crush worlds. Imagine living lifetimes together in the space of minutes, running and laughing," she pauses, some other memory bringing a sly grin to her face. It's familiar to Anita, the same one the Professor always used to wear at university galas as she span around the dance floor in the arms of some hapless, infatuated donor who clearly hadn't understood what he was letting himself in for. "Oh, and kissing, there was an awful lot of that too."

She's silent for a few seconds, her expression becoming more sombre, a reflection of remembered pain.

"Now imagine that person forgetting who you are, slowly, bit by bit. Little things at first. The colour you like best, or your favourite book. Then big things. Promises you made, the way you like to be touched," a sardonic smile "how you take your tea. And all that's left are rules that you have to follow, secrets that you have to keep. Eventually he even forgets those, and every time you meet there's still running and excitement but there's no laughter any more. He's so young, so angry, so afraid." There's too much pain in her voice, like every part of her is breaking all at once

Anita grabs her hand, seeking to offer some comfort, just like the Professor did for her in the Library, in those final, terrifying moments before she woke up here, but then River Song looks up, and her face is radiant.

"But here," she says, and now they're standing in the Gamma Forests, trees all around them, stretching into the sky forever.

"Here, there's no universal order at stake."

Another flicker and they're on top of a pyramid, gazing out at miles and miles of shifting red sand.

"No rules."

Professor Song turns to her, takes hold of her other hand and they're soaring above a vast purple sea, giant fish leaping out of the water as they fly overhead.

"No secrets."

Flashes of lightning, hammering rain, black mud that should stain their clothes but doesn't.

"No lies."

Finally they're back on the balcony, and Anita doesn't think she's ever really seen the Professor-River-properly before now, hair decorated with star dust, sea spray glittering on her skin, and an intense, feral happiness flooding her face. They're still holding hands, and River twirls them round and round until they collapse on the floor, peeling laughter pouring from their throats.

Then Anita feels time shift around her again, and it's dawn. The light sets River's hair aflame, a burning halo around her head as they recline on a vibrant green meadow, watching the sunrise. The wildness is gone from River's features now, replaced with a deep peace as the rays stroke her face.

"Here, I'm free."

Anita decides to ask personal questions more often.