Sometimes people spend whole lifetimes just living. They live, and breathe to live. They see the beauty, they see the pain, oh yes, especially the pain. But they stay there. They stay at the surface, and they do not understand. Sometimes they try to, then they get too tired to; or, they accept what others tell them – to just believe. Some people believe in God, some believe in magic and fairies, others yet, believe in themselves. Aren't we all just stories in the end?

Sometimes, all you need is that one tiny spark. Just one. For the enigmatic River Song, it was in that split second when she hovered for a moment – whether she should knock the Doctor unconscious – that she realised so many things. That split second stretched miles, deep into time and space, and right into her soul.

She was sent away, of course, but there was a nagging feeling within her that she just could not get rid of. So she followed her woman's instinct and went back. As she approached the doorway and saw what the Doctor was doing, she understood. He was going to sacrifice himself to save his friend, and some 4000 other souls who had been trapped in cyberspace for over a century.

That split second, she loved and hurt. She loved this man so much, even though she had never seen his face before. She thought she had loved him so much more when they declared their wedding vows in an aborted timeline, she thought she loved the face of a cheeky man who donned bowties and braces. But at that moment, she could not love him more. She loved him so much that it hurt. She loved him not because he loved her – he didn't even know her – no, she loved him because he loved people who didn't know him, loved them enough to give of himself.

That split second, she hurt. The love went deep, deeper than before, so the hurt cut deep, deeper than any hurt too. She understood the consequences of his doing; he was going to die. He might or might not have a chance, but it hurt. This man, whom she knew better than anyone did (or she'd like to believe), was going to leave her. Leave the world. She hurt because she was his wife, but he didn't know that yet. She hurt because she knew if she had not sent him the message, he wouldn't have to die. She was sending her own husband to his death.

That split second, she was loved. Centuries of adventure and courtship danced through her mind in vivid colours. She murdered him and revived him. He was the reason she had twelve thousand consecutive life sentences to her name, yet she gave away her freedom freely to ensure his safety. He was her parents' best friend, but he would know her even before he met her parents. Their relationship was the epitome of Time and Space – which really was just undefinable. This undefinable quality of their relationship defined their relationship, defined who they were. They were beyond paradox, beyond contrast, beyond a definite polarity. They were a mesh of Time and Space, of good and bad, of love and hurt, of selfishness and selflessness, of laughter and tears. Yet ultimately, who's to say there must be laughter without tears, love without hurt, or good without bad?

That split second, she had to make a decision. But really, there was nothing to decide. Her mind and hearts and body acted in unison, so really, there was no stopping her. She knocked him out cold.

As she took quick steps to sit herself in the chair, hooking up to CAL, she couldn't tell whether she loved or hurt, or was loved anymore. Her insides clenched as she realises he had always known she would die this way. She didn't want to go, but she would not have it any other way. In that split second she had realised all the beauty, all the hurt, and all the in-betweens. Was it understanding? Did it even matter?

The Doctor roused, and was distraught that River took his place. He does not understand, but really, neither does she. She knows why she's doing this – it was both rational and irrational. Rational, because she cannot let him die, not now. Irrational, because every single cell of her body both protested against death without saying goodbye to her Doctor, yet propelled her towards saving the Doctor. She doesn't know why she's doing this – it was both fear and love. Fear, because she would never see him again, and fear drives people to do things. But love too, because she loved him so much; she wants him to experience all the wonderful things she'd experienced in their relationship, and love drives people to do things. She understands, and she doesn't. In the end, she looks at the Doctor in the eye, and falls in love all over again. This was not her Doctor, but this was the same person. So she bores her eyes into him, remembering him, remembering him, remembering them, remembering Time and Space, remembering all the –

You and Me, Time and Space. You watch us run.