Doctor Who: How The Doctor Got Her Darkness Back

The Shelley Influence

'The Haunting Of Villa Diodati' is based on a very famous real-life event, that saw Lord Byron and a few of his contemporaries hole up in the titular villa during a dark and stormy night. Taking approximately all the drugs in the known world at that time, washing them down with absinthe, telling scary stories, and following it up with a hacked-together seance; this was the night that inspired Mary Shelley to write Frankenstein.

A little aside here, a subtitle for Frankenstein was The Modern Prometheus. Just as the Prometheus of Greek myth stole the secret of fire from the gods, so Doctor Viktor Frankenstein stole power over life and death. And, just as Prometheus was tortured by the gods for his transgression, so Frankenstein's life was torn asunder by what he'd done.

A common misconception is that the Prometheus of that title refers to the creature Frankenstein creates, rather than the scientist, and this is reflected in the episode. Mary Shelley, upon facing the creature behind much of the haunting events that had dominated the night in the villa, calls the Lone Cyberman a modern Prometheus.

Had there not been so much going on, The Doctor herself would probably have commented on that, but she was concerned with a different Shelley.