"The Haunting of Villa Diodati" is a classic Doctor Who historical episode, with the Doctor confronting the Lone Cyberman at the Villa Diodati. Like all the best Doctor Who historicals, it's a perfect blend of sci-fi action and historical adventure, with the Doctor meeting a group of celebrated writers, poets, and philosophers, including Mary Shelley.
The setting is a perfect one for a haunted house story. This is the summer of 1816, the infamous "Year Without A Summer." It was caused by the 1815 eruption of Mount Tambora in Indonesia, the most powerful volcanic eruption in the last 10,000 years; it expelled so much ash that it affected global climate. It was an agricultural disaster, described by historians as the last great subsistence crisis in the Western world. But it also left a lasting impression on popular culture; artists like Turner were inspired by the sunsets, while early horror writers were struck by the nightmarish storms.
Just as in Doctor Who, one such group gathered at the rented Villa Diodati near Lake Geneva in Switzerland. Their party consisted of Lord Byron, who had left England after a series of scandals; his physician John Polidori; poet Percy Bysshe Shelley and his future wife Mary Godwin; and Mary’s stepsister Claire Clairmont, who had pursued Lord Byron after having an affair with him and at the time was pregnant with his child. The rain kept the group indoors, where they began reading one another supernatural stories such as the anthology of ghost stories called the Fantasmagoria. Over the course of the next three days, they gradually turned to writing their own stories. Polidor penned The Vampyre, and Mary Godwin wrote Frankenstein, published anonymously in 1818.
"The Haunting of Villa Diodati" is written by Maxine Alderton, a committed scholar of Mary Shelley's work, and it's no surprise the script is remarkably accurate. It's true that the story compresses the timescale; it suggests Frankenstein and The Vampyre were written over the course of a single night, rather than over three days. But everything else matches up pretty well. In one particularly interesting scene, the Doctor uses a Time Lord power to give Percy Shelley a vision of his death, and he is shown drowning; this was indeed his fate, with Percy drowning in a sudden storm on the Gulf of La Spezia in 1822.
Meanwhile, "The Haunting of Villa Diodati" suggests a fantastical origin for Frankenstein and The Vampyre. Polidor is presented as almost like a vampire himself, an amusing conceit. Meanwhile, Frankenstein is clearly supposed to be inspired by the Lone Cyberman itself, which Mary interpreted as a composite being made up of parts from different human bodies. This is especially ironic because for Doctor Who's original creative team Frankenstein was the loose inspiration for the Cybermen.