On a misty night in Marlow, a shadowy figure in a long black dress glides along the bank of the Thames, mourning her lost husband.

Is this the heartbroken ghost of Mary Shelley, returning to haunt the Buckinghamshire town where she finished Frankenstein more than 200 years ago?

Not quite. She starts to sing ‘Don’t You Want Me, Percy’, a twist on The Human League hit, rewritten to focus on her husband Percy Shelley’s affairs.

This is Nicola Metcalfe, creator of the Mary Does Marlow walking tour, which attempts to revive Shelley’s legacy in a town she fears has forgotten her.

The Shelleys moved into Albion House on West Street, Marlow, in 1817, months after their marriage.

Though they stayed only a year, it was here that Mary completed Frankenstein, which would go on to shape the Gothic genre and pioneer science fiction.

It was anonymously published on 1 January 1818, a common practice at a time when men dominated the world of literature.

Today the property has been divided into several homes, one of which is named Shelley Cottage.

A plaque outside commemorates the family’s time there, but Ms Metcalfe, who is from the town, says: “It does annoy us.

“The plaque says something along the lines of: ‘Here lived the poet Percy Bysshe Shelley’ and then, almost an afterthought, ‘and his wife Mary’.

“You think, ‘Well, hang on a minute. Name something that Percy wrote.’ Everyone knows Frankenstein. Do we all know The Revolt of Islam? Have we all read that?”

Mary began writing Frankenstein as a teenager during a rainy summer vacation in Switzerland in 1816, while visiting Lord Byron with her then lover, Percy Shelley.

Trapped indoors by bad weather, the group started a ghost story writing competition to pass the time.

Shelley continued writing her story, Frankenstein, when she returned home to Bath.

The anonymously published book opens with a preface recounting this story of how it was written, signed off as “Marlow”, the town where it was finished and later published.

The story follows Dr Victor Frankenstein, who is haunted by regret after giving life to a monstrous creature that begins a murder spree.

Despite his unappealing form, the misunderstood creature displays intelligence and humanity as it pursues its creator around the globe.

More than two centuries later, it is still widely read and celebrated as a defining text in the Gothic genre.

It has been adapted for stage and screen, and the most recent Netflix film version stars Saltburn’s Jacob Elordi.

Ms Metcalfe says: “To have come up with this concept as a teenager, and then to pen what is acknowledged to be the first work of science fiction ever – by a girl, a teenage girl – it’s just unbelievable.”

Last year, Marlow’s first JD Wetherspoon pub, The Grand Assembly, opened, featuring a hand-painted portrait of Mary on the wall and a “Frankenstein” cabinet full of her books and some scientific instruments.

There is an annual 10k run, called The Frankenstein, in the town but other references to Shelley’s time there are scarce.

Ms Metcalfe, who has a background in amateur dramatics, found this “outrageous” and in 2018, the bicentenary of Frankenstein’s publication, came up with the idea of dressing as Shelley to lead visitors through the town’s history.

She admits to turning the author “into a bit of a monster, really”, describing her as an “austere sort of character but quite vivacious”.

The tour blends humour, music and props with stories of Mary and Percy Shelley’s lives.

Included are tales of Percy’s infidelities and how Mary apparently kept his heart after his death.

Local history is woven throughout, but Ms Metcalfe says the ultimate goal is improving Mary’s standing in the town.

She is currently trying to convince the town council to build a permanent statue of Mary “somewhere prominent”.

“Marlow’s like a sort of a literary hub, but we don’t make anything of it,” she says.

“It frustrates me. It’s all about Michelin Stars here.

“There was no-one talking about it. I found it completely bewildering.”

The Shelleys are not the town’s only residents from the world of literature: Enid Blyton and TS Eliot also lived there.

“We’ve got all these literary connections, obviously the pinnacle being Mary Shelley, but it needs to be put on the map,” says Ms Metcalfe.

Asked if there were plans for a statue, Marlow Town Council instead stressed its pride of the author.

It told the BBC: “Marlow Town Council is proud that Mary Shelley brought Frankenstein to life here in Marlow — and that her residence is marked by a commemorative plaque on the house she shared with Percy Bysshe Shelley, a tangible link to our town’s remarkable literary heritage.”