She is only ordinary,
Only a blip in the vastness of time,
An anomaly,
A product of her history.
She is nothing special,
Yet perhaps that is what makes her
All the more extraordinary

The heart of a human, I am told, is a relatively simple thing.

It lies there, merely the size of a clenched fist, but every one of its beats (of which it averages around 72 per minute), is a mini-miracle, fuelling the even bigger miracle of the person who happens to harbour it.

It had four chambers, two for the reception of blood, and two for the sending away of blood. The blood flows through the heart in a pre-defined pathway, following two circuits. It is this pumping in and out of blood that gives the beat of the heart its "lub dub" sound, which you can hear if you place your ear to the chest of your loved one.

Relatively simple, I am told, in the grand scheme of things anyway.

When the heart stops, it is called "cardiac arrest". It this state (if you are lucky), it is possible for the heart to continue to quiver "Like a pitiful human in the face of a Sontaran Warrior" – as Strax described it, but technically known as "ventricular fibrillation". The heart continues to contract in an uncoordinated fashion, a phenomenon otherwise known as arrhythmia. As long as the heart is in this state (and has not completely ceased all electrical activity and entered asystole (flatline)) it is possible to dramatically improve chances of survival, and quickly and suddenly jolt the heart back into rhythm through early defibrillation.

Defibrillation delivers a controlled electrical shock to the heart, which depolarises a critical mass and ceases the irregular rhythm. To simplify it, it acts like a runway light, giving the body a clear pathway to re-establish its natural rhythm. The Doctor tells me that in future London, devices to deliver these shocks are commonplace, and even can be found in large public buildings, or embedded in the walls of some larger London Underground stations.

Simple, really. The more I think about it, objectify it, describe it in scientific terms, the more I see how the events of Trenzalore were nothing special – just a simple defibrillation, a common electrical restart, a normal medical procedure, easily resolved. Sure, luck played some part in the ease of recovery, but there was no reason to lose it, or lash out at Strax. I do feel some guilt at threatening him still.

But the trouble is for me, is that the heart has always been more than the sum of its parts, or its functions, or its medical terminology. No matter how hard I try to see it through a cold, calculated lens, and reason with myself otherwise, the heart is nothing but simple when it comes to her.

By Victorian standards, she is nothing special; she is a maid, working class, a woman, unmarried (well, by the standards of the Church, and to a man at least), and of unusual "preferences in companionship" – a 'Tom', if you like. But I have never put much stock in the pre-defined standards of ape society, and these facts about her only serve to make her all the more extraordinary to me; because of all she has managed to do for me. An unremarkable woman by all parameters of the times, but she saved me, changed me, moved my life, and brought out feelings in me that once upon a time seemed impossible. A proud Silurian Warrior, floored by an ordinary homo-sapien.

As she sighed,

The warmth on the tip of her tongue
Seemed to melt the frost on my window

And let in the sun,

The same I once shunned

And belittled

For a life that never begun.