A light discourse.

So, it’s worth thinking about light, if you’re writing a historical novel, particularly if you live and/or were brought up in a city. We moderns are as unaware of light as a fish is of water. We switch it on where we need it, and the night goes away in an even wash of colourless white illumination. Even when we switch it off, outside the windows the lamps keep shining and all our streets are yellow and the shadows are madder-brown.

Photographers and painters spend their lives acutely aware of the light – it’s angle, its intensity and its colour, and the fall of the places where it is absent. But writers have a tendency to ignore it, because we are less visual beings and we’re too busy worrying about plot and characterisation, and wondering if we’ve got too much description rather than too little.

I think that’s a shame, because if you’ve ever sat in a room illumined only by candlelight, you’ll know that it’s an entirely different experience from sitting in the same room under electric light. There’s a sense of human impermanence and fragility from the fact that the light is so vulnerable – too sharp a draught and those little flames that flicker so brightly on the end of their wicks could snuff out. The darkness is behind them all, waiting for its chance, and it can be felt, like a prowling presence just outside the protective circle.

Candlelight is also far more beautiful than electric. The colour of candlelight is the colour of the light before a storm – thick, golden and sweet. Garments look richer in it, faces look smoother, soft-focus, dusted with gilding. It’s a warm light that encourages quiet voices and secrets, intimacy and intrigue. And it casts more shadows.

Out there, beyond the charmed circle, outside the light, who knows what lurks? Even the rooms of your house fill up with hidden things, whether that be murder clues or secret trysts or supernatural terrors.

If you’ve ever walked outside, in the countryside, where there is no light pollution, on an overcast night, on your own, you’ll know you can feel buried alive even in the open air. And if you’ve done the same under a full moon, when the sky is indigo and green as a bad bruise, and all the world is tricksy silver-blue, you’ll appreciate how hard it was for our ancestors not to believe in elves and wights and headless horsemen. Under that lunatic light, you can practically see them wherever you look.