The trailer is well-cut, shows some pretty scary images, and some key points of the story to make it very intriguing. In an interview with Spanish film magazine Fotogramas, Strong said that the film is "a classic detective story, with some science-fiction elements." Dorado cited films such as Vertigo and Chinatown as inspirations, and said that the film is a kind of cryptic puzzle for the audience to solve.
I've enjoyed Dorado's short films (he's twice been nominated for the Goyas (Spanish Oscars)), and other Spanish fantastic film directors (such as Nacho Vigalondo and Eugenio Mira) seem to be making the successful transition to English-language film. While there is no date for release in North America or the UK, it is due to be released in Spain at the end of October.