It’s a story that could come out of any teen drama or modern soap. A sweet-talking rebel turns up to a family’s house, inveigles his way into his friend’s daughters’ affections – and knickers – and the 16-year-old who’s prone to bouts of teen angst and grand passion ends up thoroughly smitten. Not to mention up the duff.

Helen Edmundson’s retelling of the domestic nightmare of the Godwin-Shelley household could largely be transposed to a soap opera setting with a few tweaks, since it focuses on the interpersonal dynamics between Mark Shelley (nee Godwin), her idealistic, debt-ridden father and romantic and equally debt-ridden lover Percy Bysshe Shelley.

Things kick off with an expressive dream sequence where Mary dreams of her dead mother (young, in childbirth, naturally) but it all settles down into something of the domestic routine. Mary’s father and stepmother Mr and Mrs Godwin sniping at one another, young half-sister Jane being ditsy, Mary throwing herself around with the pained outlook of a My Chemical Romance fan.

Somewhat disappointingly this is no hysteria-fuelled baroque nightmare like Ken Russell’s Gothic, it’s a slow-burn family melodrama with occasional flashes of welcome humour that render the Regency-era play a little bit… Blackadder.

One can almost hear Mrs Miggins castigating Shelley for being a “big girl’s blouse” – and some audience members may have been grateful for such an interjection with Shelley’s interminable wittering about the beauty of political justice and community.

As it is the guileless, idiotic Jane who cuts through the dreary angsty idealism of Shelley and Mary, but even she turns into a Mary-lite, knocked-up by a contemptuous Byron and subsequently idiotic and affected.

Only poor Fanny – the eldest of the three sisters – comes out of the play well, which is unfortunate as she also ends up dead (suicide, laudanum, naturally).

There are flashes of something deeper here – the habit of impetuous romatics to leave a trail of utter misery in their witless wake; Mary’s troubled relationships with her family and Shelley and the resulting genesis of Frankenstein; the portrait of feckless young men as implicitly unable to keep their Doctor Johnsons in their trousers; and the need for creative people to suffer for their art. But overall the play seems content to trundle through the extended family’s mishaps.

Mary Shelley as a production is enjoyable and strong, with committed performances from everyone, but virtually to a man the entire cast of characters are nothing less than insufferable bores – it makes it hard to empathise with them or care much about their various misfortunes and fates.

In the end it’s a line from Blackadder himself that sums it all up: “There’s nothing intellectual about roaming around Europe in a big shirt trying to get laid.”

Mary Shelley
Liverpool Playhouse
Until Saturday 12 May