A clock strikes eleven – much later, we'll learn the significance of that hour – and a man with moustache and mutton-chops walks onto the stage. A man, not a gentleman; this is Inspector Albert Thorne, who's spent his life policing the parts of London where the Victorian monied classes dare not tread. He's here to tell that story, to speak for the disadvantaged… and inevitably, he reveals a few things about his own life along the way.

The Inspector's monologue is as much about a place as it is about particular crimes, and actor-playwright Steven Langley paints a vivid picture of poverty in Whitechapel and Bethnal Green. He draws some parallels with the present day, talking about immigration and the process of becoming a Londoner, but this is primarily and firmly a period piece – transporting us into a Dickensian world of garrets, slums and workhouses. Even a century on, this reality has the power to shock, and the Inspector's authoritative anger is an effective conduit for some uncomfortable truths.

The first few anecdotes we hear are a little disconnected, and a clearer ongoing plotline might have helped me engage with the characters we meet in the second half of the play. Here, questions of class and privilege come to the fore, building to an exciting and convincing showdown – a story that again has clear contemporary parallels, played out beneath an iconic landmark that still stands in London today.

The framing device of a Victorian-era lecture certainly has potential, but it could do with being more confidently and forcefully portrayed. Halfway through, I honestly wasn't sure if we were still sitting in a lecture hall, or if the action had now moved elsewhere. One haunting passage, where Langley slows his monologue almost to the point of silence, gains an extra electricity from the sense that the inspector is breaking down in public; but more often the lecture format feels limiting, denying him some of the trappings of theatricality which could have helped his stories come alive.

The opening scenes in particular suffer here; the story we're hearing is visceral, but the delivery is overly measured, a bit too much like Inspector Thorne is reading a novel aloud. Later, when that controlled façade begins to crack, the language grows lyrical as our hero reflects on the fact that he couldn't achieve more. I think I understand the character progression Langley is trying to portray, but some of the switches in mood – from authority to melodrama to tragedy – were too sudden and unheralded to fully work for me.

The ending will divide opinion. I can't explain much without spoiling it; I'll just say that it seemed fitting to me, but I'd have enjoyed it even more if there'd been some clues here and there, a realisation that the truth had been staring me in the face the whole of the time. Overall then, Victorian Gothic is an enjoyable treatment of an interesting and important theme, but perhaps it needs a little more structural development to fully deliver its potential.