A/N: Many a thanks to my lovely beta, Prisci.

Disclaimer: Sherlock. It's not mine.

Gravity. Forever there. Constant. Unavoidable. That overwhelming force that pulls a body towards the centre of any other physical body with mass. That force that influences every second for everyone.

We can undergo the sensation of leaving it - to take off in an aeroplane, to float in the sea, that light as a feather feeling - but we can never truly escape it; the feeling is fleeting.

The gravity of the earth controls everything. It takes us and wraps us in its strong arms and pulls us down, soft enough to give us the ability to land and hard enough that landing in the wrong place at the wrong time can shatter us completely.

It's greedy, gravity. The greediest thing in the universe.

It's the Earth's gravity that keeps mankind on our planet's surface, holding us down. Even those who escape come back in the end.

You jump from the surface of the Earth and it pulls you back, bringing you lightly to its surface.

You - or the world's only consulting detective - jump from above the surface of the Earth - for example, from the roof of a hospital - and it brings you still to the surface, no longer lightly, but with a force, a force strong enough to tear apart worlds or, at the very least, to tear apart lives.

But the gravity of the Earth is not the only force pulling us towards something, even when it would be easier to stay away. Sometimes the gravity of a person is strong enough to keep us forever tethered to them, even when we want to just walk away.

Molly Hooper never intended to love Sherlock Holmes. He was, to put it kindly, a complete douchebag. In fact, after the first time she met him, she prayed he would enjoy one of the other pathologists more. She knew her faults, she didn't need some cocky detective to tell her of them. But he must have found even worse faults in her coworkers. Because he was always there. Always. And then one day, she realised she didn't hate him. Quite the opposite, actually. The day after that he asked if she would let him into the lab.

"Why?"

"An experiment." And then that look.

"...Okay."

She was trapped. She tried to distance herself, when she realised that she was just being constantly sucked in, constantly drawn closer to his hidden interior. It frightened her, this inescapable force. So she tried to find someone else, someone who's gravity would pull her in, would free her from the gravity of Sherlock Holmes.

But serial killers weren't exactly her cup of tea.

And she was stuck, unable to go anywhere. Lost within the gravitational pull of Sherlock Holmes. And she knew she would never escape, no matter how hard she tried. It was tortuous, the knowledge that she would never be able to live a normal life, hung up in the gravity of something so grand it would never notice her.

The world, with its gravity, makes all the difference to its inhabitants. But the individual inhabitant is nothing to the world.

Sherlock Holmes was Molly Hooper's world, she was constantly aware of him, constantly influenced by the way he treated her. But she didn't count, not to him. She was just a small particle, so small she couldn't be seen, lost in the field around him.

But, sometimes, even the world needs a saviour. Something to depend on.

What do you need?

You.

Sometimes, gravity is overwhelming. We search for ways to escape it, to have control over our lives, over our bodies.

But, one day, we learn that we need gravity. Without it, we float through life, unable to find something solid, something to hold on to. So we respect it. And we use it.

Because gravity, of every type, is the very essence of life.