The prequel in the franchise fills in the background of how the war between the vampires and lycans grew to what it was in the original. The characters that are pulled over are primarily from the original film not focusing much on the background that was filled in with Evolution. The film takes place after the events of the before credit scene in the Evolution but long before any modern day vampire and werewolf batting in the modern city.
The actual time is not clear if it was told somewhere in the film but the costumes and behavior hint at medieval. The lycans are slaves to the vampires though some of them cannot change back into human form and are monstrous beasts that prowl the woods killing nobles and other weak humans that come to the vampires for protection.
Viktor (Bill Nighy) is the leader of the vampires as the other two elders sleep. He discovers Lucian (Michael Sheen) who is the only werewolf that can change back to human form. They use his blood to convert other slaves into werewolves that they chain up and use for protection of the castle walls. Viktor does not know that his daughter Sonja (Rhona Mitra) has fallen for Lucian. Sonja is a skilled warrior who fights the wolves in the woods.
With the help of Raze (Kevin Grevioux) from the original, Lucian leads a rebellion freeing the enslave lycans and building an army to fight Viktor. The action is pretty entertaining despite a shift from the gunplay of the two original films to a more medieval form of battle with swords, arrows, and spears. The special effects for the werewolves had increased further along to make them more enjoyable to watch.
Both Sheen and Nighy are quality actors who bring their expertise to the film, but the simple sets and blue tinge make this just another addition to the franchise with only a few new things to add to the story. The move often revolves around the politics of the vampires' rule which is still one of the dullest parts of these films. The story, like the others, focuses on another forbidden union between species, this time Sonja and Lucian. Ultimately, the motion picture leads to the events foreshadowed in the previous films and the subsequent war.