The last time I saw Sean Bean on the telly and paid any real attention, he was being moydudd in typically nasty fashion on Game of Thrones. Yes, it’s been that long. In fact, I can’t really remember seeing Bean in anything as memorable since Lord of the Rings.

That was until ITV drama The Frankenstein Chronicles, and boy is Bean ever back. He is slightly fuller of face and mercifully shorter of barnet, but the magic that makes this gruff, gritty actor so thoroughly watchable is still there.

He plays surly 1820s river policeman John Marlott, who is tasked with finding out who is behind a hideous creature washed up one cold, grey morning.

What looks like the body of a child is in fact made up of seven different youngsters, their component parts sewn together. No wonder the copper who stumbled across it heaved up his breakfast.

Marlott is charged by the plummy-toned Home Secretary to find out who cut up the children and reassembled them, and whether they are deliberately trying to sabotage an act of Parliament prohibiting the work of bodysnatchers.

It’s not exactly what the river policeman is used to, but he’s not the sort to defy orders. Hooking up with sidekick Nightingale, who quips he landed the job because he “got lucky”, Marlott learns local urchins are terrified of a “monster” who comes at night and spirits children away – but who is it?

It could be Billy, a violent gang leader with a small army of young kids but none of Fagin’s charm, who almost traps Marlott as he tries to track down a missing girl, Alyc. Luckily for the copper, a full chamberpot and guns that only fire one bullet means he escapes by the skin of his teeth.

It is a truth universally acknowledged that you can’t have a happy detective, and so it goes here. We’re offered glimpses of Marlott in a happier, cleaner time, when he was a devoted husband and father – but hints of some great tragedy explain why he’s now a shadow of his former self as he goes about his work.

The Frankenstein Chronicles is unusual as it just doesn’t feel like an ITV drama. There’s a richness to the production values and a depth to the script that isn’t normally there. Nothing feels rushed or glossed over and the attention to detail is remarkable; peeling walls and endless grey filth juxtaposed with light and elegance and colour, marking the boundaries between the two worlds  – impoverished and wealthy – that Marlott knows.

Epic wide shots reveal more: it’s relentlessly cold and muddy underfoot but in the distance, rising up there is beauty and grandeur. Something to aspire to. Yet scratch just beneath the surface and the rot’s still there.

Bean is mesmerising as Marlott. At first, he comes across as a little wooden, but then you realise he is a man barely holding himself together, the wound of his loss open and raw and deep, but all conveyed with such delicacy and skill that it’s impossible not to watch.

Things are going to get a lot bleaker for Marlott, I’m sure, but if the rest of The Frankenstein Chronicles is as good as this opener, I for one will be with him every step of the way.

Scheenagh Harrington