With the TARDIS doors thrown open and bowls of popcorn in hand, they watched the sun throw out a deadly solar flare, they watched it, breath held, as it reached the Earth. The excess oxygen ignited and the planet looked like it was on fire. Then they watched as it disappeared and the Earth looked the same. After the last shock waves of the flare faded away, they closed the doors and finished their popcorn in silence, the Doctor pacing around the console, occasionally grabbing some popcorn from either Clara or Aderyn.
By the time they arrived at Clara's apartment, the world was unchanged, everyone completely unaware of the disaster that could have been. They stood on the balcony and watched as the trees began to disappear in swirls of golden sparkles. Aderyn and Clara leaned against the railing, each had a bottle of beer in hand, Aderyn tapping rhythmically against hers, her nails tinkling pleasantly against the glass, a noise Clara forever associated with the vanishing trees. The Doctor stood behind them, leaning against the doorframe. He watched the two women as they looked out across the city, smiling in awe and wonder.
"This is amazing." Clara breathed "How will they explain this is the morning?"
"You'll all forget it ever happened." The Doctor said.
Clara turned to look at him "How can we forget an overnight forest?"
The Doctor shrugged "You forgot the last time. You remembered the fear and you put it into fairy stories. It's a human superpower, forgetting. If you remembered how things felt, you'd have stopped having wars. And stopped having babies."
They watched in silence as the last of the trees disappeared, momentarily bathing the world in a cheerful gold glow.
"I should get going." The Doctor said eventually "You coming Addy?"
She shook her head "No, I've got a couple of bits to do before I head home. I've got my vortex manipulator with me." He said quick goodbyes and they listened to the departing TARDIS, staring out over the city.
"You were really good with the kids, and they loved you when you were teaching. Ever thought about having your own?" Clara asked.
Aderyn didn't answer straight away. She swirled what was left of her beer around in the bottle before downing it. Clara was preparing to apologise for asking such a question when Aderyn cleared her throat.
"Thought about it for a while. But I couldn't give him up." She said quietly.
"Give who up?"
"The Doctor." Aderyn stepped back from the balcony, leaning against the wall, arms crossed, but still staring fixedly at the view. "It's all well and good getting married and settling down, The Doctor would visit every now and then. But never for long. There would always be another adventure waiting for him. He'll go, and you'll want to go too. If you're pregnant, he won't let you. But then, you have the baby and it's all great, you can leave the baby with the other half or a babysitter and run off with the Doctor in the TARDIS. But then there's a close call and you realise that, one day, you could go with the Doctor and not come back. You'll realise that the poor kid you've left at home could grow up without you. Or worse." Aderyn fell silent again, frowning deeply as though trying to find the right words. She was lost in her own dark fears, only fading back to reality when Clara took her empty bottle from her hand and gave her a fresh drink. She took a swing.
"What could be worse?" Clara asked.
"Years ago my own death wouldn't have scared me. If anything, I'd have welcomed it. Then along came the Doctor. He gave me something to live for. If I had kids, and then travelled with the Doctor, it would only take one life or death situation for it to be his life on the line, not mine. He would never say it, but I know that would be the case, regardless of whether I had kids or not. It's just who he is. But it would be so much worse if I had someone to go home to. It would take one close call for him to put himself in harms way to get me out of it. And it could be a situation he wouldn't get out of." Aderyn spoke quietly and slowly. There was such pain in her voice that Clara had to bite back the overwhelming sadness that washed over her.
"You didn't want the risk." she said quietly.
"I didn't want to stop running." Aderyn said with a heavy sigh "Imagine you and Danny get married, have a kid, and you go with the Doctor. You should know by now that being the Doctor's companion is never relaxing. Do you think the Doctor would allow it to be the same?"
Clara shook her head. She looked down at her own drink, uncertain what to say but strangely comfortable in the silence. "How long have you been travelling with the Doctor?" she asked eventually.
Aderyn took a swing of her drink, again tapping her fingers on the bottle, but this time as though counting "On and off for fifteen years."
"You must have seen some amazing things."
Aderyn's face darkened "I've seen stars form and die, I've seen civilisations burn. I saw Pompeii drown in lava, visited a planet that was covered in a library, run from statues of Angels that send you back in time, I've been erased from time, and I've seen time stand still. I've met many races and species. I've seen people die, a lot of people. And I've seen people born."
Clara let out a breath of laughter "I know I've said it before, but you really do sound like him sometimes."
Aderyn finished her drink and chuckled "I know. I even went a bit Scottish then."
"That's not what I meant."
Aderyn smiled kindly at her "I know. It's an occupational hazard." They shared a smile and a laugh. They stood in comfortable silence, still looking out over the balcony. They watched the headlights of cars going passed below them, knowing that the world was none the wiser, not harmed or changed by the events of the day.
"I should go. There's a few bits I need to sort out before heading home." Aderyn said.
Somehow Clara knew that things were going to be different between them now. Something had passed between the two of them, something Clara couldn't define.
Before she turned for the door, Aderyn hesitated. She took a small card from her pocket and handed it to Clara. "That's the number for Kate Lethbridge Stewart. If there's any problems, if you get into a situation neither you or the Doctor can get out of and you can't get hold of me, give her a ring. She'll know what to do." And she left, whistling a haunting tune as she closed the door behind her. A few minutes later, Clara spotted her walking from the building. Even in the noise of the city in the evening, Clara was certain she could still hear Aderyn's whistling as she crossed the street and disappeared down an unlit alleyway.