apologizes to her on behalf of Ronnie, and says that he makes them all look bad, making it clear that he too is a vampire. Scully belatedly realizes she has been drugged, and before she loses consciousness, she sees Sheriff Hartwell's eyes turning green. At the RV park, Mulder finds Ronnie. As he tries to arrest him, Mulder is surrounded and overwhelmed by a group of people with glowing green eyes. He wakes up the next morning in the RV park, in his car, where he is rejoined by Scully. They are both unharmed and the vampires have disappeared. Back in Washington, they give their unified report to Skinner, who is dumbfounded by what he has heard. Production Writing and filming "Bad Blood" was written by Vince Gilligan, making it his fifth writing credit for the season. Aware that an episode script was due after the Christmas break of 1997, he had been working on a script that would have taken the form of an Unsolved Mysteries episode, with unknown actors playing Mulder and Scully and Robert Stack appearing in his role as narrator. Under pressure to complete the script, Gilligan scrapped the idea because he "just couldn't figure out how to do it". (The series would later explore the idea of an X-Files crossover in the guise of non-fiction with the seventh season episode "X-Cops", also penned by Gilligan.) With the help of executive producer Frank Spotnitz, Gilligan came up with a new idea inspired by an episode of The Dick Van Dyke Show, called "The Night the Roof Fell In", in which the main characters, Rob and Laura Petrie, tell different versions of a fight they have had. Gilligan said of the idea, "I just thought it was a cool way to tell a story." With two versions of the same story taking up much of the episode, Gilligan knew that he would have to keep the plot simple, and so he settled on a vampire story that everyone could easily follow. Both Mulder and Scully's unique versions of the episode were filmed back to back, utilizing the "exact same sets and camera angles". The RV park that was featured in the episode stood on the site of an old sawmill that had burned down; in fact, this mill had been used by the show in the fourth season episode "Gethsemane". Casting and effects Luke Wilson was cast