House of Dark Shadows (1970)

Young David Collins has gone missing from his home on the Collinwood Estate. While others try to find him - he in reality playing a prank in just hiding - incidents occur not only on the estate but in town, where some have been victimized by some unknown creature who has left a pair of puncture wounds in their neck. Those that have not survived have literally been drained of their blood by the creature. Following the start of these incidents, a long lost relative of the Collins from England, Barnabas Collins, arrives at the estate, the rest of the family knowing he being who he says he is by the uncanny resemblance to his namesake, who lived approximately one century ago and whose portrait hangs in the main house. Barnabas decides to stay in fixing up the old house on the estate with the help of Willie Loomis, who had just been fired by the family patriarch, Roger Collins. Barnabas' decision is strengthened when he finds a reason to stay in being able to complete something he was unable to do when he had been at Collinwood previously with Jacqueline DuPre. With the creature attacks continuing, speculation starts turning to the thought of a vampire being loose, Dr. Julia Hoffman, in examining the victims, believing she having a solution to stop the attacks for good. Her ulterior motive has some effect on what happens.