What has been labelled ‘New Horror’ cinema has opened up its boundaries to incorporate signs specific to social and political events that accompanied and followed the events of 9/11. The reality of terror is transported into the fictional universe of horror. This article presents an interpretation of New Horror cinema using Yuri Lotman’s theory of the semiosphere and Wilma Clark’s extension of his theory in order to engage in a critical rethinking of how genres intersect with culture. The primary focus is on contemporary horror films that function as allegories that address post-9/11 and, in turn, to apply Lotman’s theory of the semiosphere and the concept of cultural ‘explosions’ to account for the generic shifts that have transformed the structure of the horror genre.