Underworld is a 2003 action horror film directed by Len Wiseman and written by Danny McBride, based on a story by McBride, Kevin Grevioux, and Wiseman. The film centers on the secret history of vampires and lycans (an abbreviated form of lycanthrope, which means werewolf). It is the first (chronologically, the second) installment in the Underworld franchise. The main plot revolves around Selene (Kate Beckinsale), a vampire Death Dealer hunting Lycans. She finds herself attracted to a human, Michael Corvin (Scott Speedman), who is being targeted by the Lycans. After Michael is bitten by a Lycan, Selene must decide whether to do her duty and kill him or go against her clan and save him. Alongside Beckinsale and Speedman, the film stars Michael Sheen, Shane Brolly, and Bill Nighy.

Plot

For generations, a secret war has raged between vampires and Lycans, an ancient species of werewolf. After years of fighting between the two enemy races, the vampires have seemingly gained the upper hand following the death of the Lycan leader Lucian at the hands of a vampire named Kraven, who subsequently became the second-in-command to the vampires' triumvirate of leading elders. Selene, a member of an elite group of vampire assassins known as "Death Dealers", longs for revenge against the Lycans, who murdered her parents when she was a child.