Swindells uses the classic conventions of Gothic horror: a dark old building, a vampire, a graveyard, Whitby itself (Dracula's landing point in Stoker's novel). The book works brilliantly as an introduction to the Gothic genre.
Fliss acts when adults would not believe her and when she has every reason to be terrified. Her courage is the novel's moral centre.
Room 13 only exists at certain hours. The hotel looks ordinary; Ellie-May looks tired. Things are not what they seem.