Blood Enemy is a non-canon prequel to the Underworld series before the events of Underworld and Underworld: Evolution. It is written by Greg Cox, who also wrote the novelizations for Underworld, Underworld: Evolution and Underworld: Rise of the Lycans. Notably, Blood Enemy directly contradicts Underworld: Rise of the Lycans and parts of Underworld and Underworld: Evolution. Blood Enemy was released on .