I should have crushed you under my heel the day you were born.
Underworld: Rise of the Lycans is the prequel to the previous two Underworld films. It tells the story about what led to the werewolf/vampire feud, with bloody energetic results.
In core essence this is Braveheart/Spartacus, only in CGI laden horror/action form. Michael Sheen buffs up into Karl Urban, who as Lucian (bad ass Lycan) leads his species to a bloody revolt, and Kate Beckinsale has made way narratively for Rhona Mitra, who sexes things up. The action is pulse raising and the Gothic designs and atmospherics are first rate, while the battle royale finale is fit to crown any genre film of its type. 
Problems are evident, though. The constant flow of CGI blood becomes irritating after a while, and Bill Nighy (in spite of being a franchise regular) is still looking miscast! But it has proved to be a series with hairy legs and fangs that refuses to die, a popcorn munchers dream. So enjoy the spectacle and the screenplay homages, and I'll have a bag of tortilla chips and a choc ice please. 6.5/10