Task: Question Answering
Input (English): Passage: It is Halloween in the small town of Pitchford Cove located somewhere in New England, and five high school friends, Phil, Mary, Mitch, Vinnie, and Melissa, plan on making it a night they will never forget. They steal outfits from the town's historic museum and come upon other old artifacts, including an old trunk encasing a paper scroll which contains an ancient curse. When Melissa, latent sorceress, recites the curse at the local cemetery, things take a turn for the worse.
The town's dead, led by Melissa's great-great-great-great-grandmother Lucinda Cavender, a witch who was put to death 300 years earlier, rise up from their graves and roam the town. As Melissa, Vinnie, Mitch, and Mary enjoy themselves at their annual Halloween costume party, Phil encounters a mysterious girl, named Sandra "Sandy" Matthews, dressed in a vintage 1950's cheerleader outfit, who warns him that the whole town is in danger.
Meanwhile, Lucinda and the various undead crash the costume party. At first, nobody pays much attention to them since everyone is in costume. However, Lucinda begins turning the party guests into vampires, starting with her great-great-great-great-granddaughter Melissa.
When Sandy discovers that Phil and his friends recited the ancient spell in the cemetery, they realize that the whole town is being overrun by the living dead and decide to team up to break the curse. The only way to do so is to find the Grenville Spirit Ring inside the grave of a witch-hunter Nathaniel Grenville - who, coincidentally, was Phil's great-great-great-great-grandfather and slave owner of Lucinda Cavender, her arch-nemesis - and use it to undo the curse.  Phil and "good ghost" Sandy must restore the town to normal by midnight before it is too late and the curse becomes permanent. 
Question: What is the last name of the person who starts turning party guests into vampires?
Output (English): Cavender.