Years ago I discovered Anthony Trollope and read a number of his books on the trot – what I always do when I fall for an author. In one of them – I can’t remember which – there’s a scene that takes place in the evening. A character comes into a room and can’t make out the faces of everyone gathered there. It took me a while to see the scene with 19th-century eyes, when light levels were low and candles expensive.

We do experience darkness these days, but there are always light switches to be fumbled for. And in the city it never really gets dark.

I was thinking about this when I saw – experienced — took part in? Punchdrunk’s immersive performance today. The Uncommercial Traveller is based on Charles Dickens’ writings about his London walks. After an audio tour guided us through Hackney we ended up in an empty shop that had been transformed into a 19th-century eating house. We stumbled in from a bright sunny day into a deep obscuring gloom. When I was told where to sit, I almost missed the bench and nearly landed on the floor. Gradually our eyes adapted, but the mystery of the low light remained and with it came a powerful feeling of stepping back into time.