Underworld - Greg Cox

Vampires and werewolves. Sworn enemies for over nine hundred years, they have fought a secret war in the shadows of the modern world, pitting undead strength and intelligence against feral rage and cunning. Now, in the hip Gothic streets of modern-day Budapest, the ancient conflict takes on an unexpected twist. Selene is a Death Dealer, a vampire warrior dedicated to the destruction of the hated Lycans. Michael is a werewolf, an innocent American newly infected with the lupine curse. Against all reason and history, they find themselves drawn together even as the grisly inhuman war rushes towards its nightmarish climax. They have no idea of the power their unlikely union can unleash -- or of the terrifying secrets that will be revealed in the unearthly realm of UNDERWORLD.
Love, honour and loyalty ooze beneath the blood of the next big Dark Fantasy franchise of the year.