A/N: Hi all, just a quick update for now. It's been a while since I've done anything for this challenge and I so desperately wanted to write another one-shot.

This is the first time I've ever written Twelve so I hope it's alright. I wanted to do something other than 10/Rose really and the prologue scene from 'Listen' where we see the Doctor under the water inspired me to write this.

Also, I've decided to keep the chapters separate now and have them as individual one-shots. I'll post them all on AO3 under the series 30 Prompt Challenge. Just feel that I want to keep old and new work as separate as I can

Underwater

He'd been all sorts of places during his long life. Anything you could imagine and he'd been there. He had seen thing your mind couldn't possibly conceive and all of it, all of the time, left him in a sense of awe. It was noisy and chaotic and he never tired of it. Always running; always eager to go on to the next great adventure; never, for one moment, standing still.

But if there was one place he knew he would always find tranquillity, it was under the waves of the oceans on the planets he visited.

His mind as usual was running a mile a minute, while he worked at completing a theory that had made its way into his mind.

He had been on his own for a while now, but he knew he would be back with Clara again soon. He just needed to finish this off first.

While he had been on his own, he had started listening more closely to every little thing. It was then that he started to notice the things he wouldn't normally notice. Was he ever really alone? Was anyone? Was there always something, hiding from sight, watching you with every move you made; listening to every word that you said?

Clara often told him that he shouldn't be on his own but, really, it was for the best sometimes and he was certain that this new body was better equipped to deal with solitude than his previous selves had been. He was no longer the Time Lord Victorious nor did he any longer hide himself from everything he stood for on top of a cloud in Victorian London. He had moved on and, yes he made mistakes, but he dealt better with solitude now than he ever had before. If anything, the time spent alone, allowed him to theorise and to try and make sense of the vast universe that he had long since labelled as his 'home'.

And besides, when he was on his own, he didn't have to deal with 'puny little humans' and their tiny brains; he could think clearly and not have to explain a thing.

Clara, he had found out lately, was an exception to this; he never minded when she was about.

Opening the TARDIS doors, he found himself under the waves of Planet Earth. He wasn't entirely sure which ocean he was under, but as he looked out at the vast darkness ahead of and around of, he almost forgot what he was here for.

He watched as the ocean life swam past him. He couldn't help but smile. Humans sometimes forgot that there was almost a completely different planet beneath them; beneath their pavements and towers and noise there was a completely different civilisation living beneath the surface of the waves they surfed and rode. It was calmer, more organised. There were no wars and life continued in the ways it had done for millennia. If only every place he visited could be like this, then the universe would be a much better place.

Eventually he got what he needed and closed the TARDIS doors; he had some more theorising to do before he told went back to tell Clara what he had discovered.

He made a mental note to come back the next time he dropped Clara off back to her life. Who knew what else he would discover?