Penny Dreadful

Penny Dreadful is an old term used during the nineteenth century to refer to cheap popular serial literature, and it could be interchangeable with penny blood, penny awful or penny horrible. It means a story published in weekly parts, with the cost of one (old) penny. The main plot of these stories were typically sensational, focusing on the adventures of detectives, criminals, or supernatural entities.

The show is using many metaphors to point out the hidden or dual nature of the main characters. One of them is shooting scenes in reflective surfaces like mirrors. Most notably though is the dark versus light depiction of Vanessa and Mina.

The language used in season 2 (Verbis Diabolo) is a fictional amalgam of Aramaic, Ancient Greek, Latin and an obscure Arabic dialect called (in phonetic English) "Kan Allah Musali-Algins". The language, Verbis Diabolo was created specifically for the show by the curator of the London Historical Societies Emeritus Professor of ancient languages.