Doctor Who: Vampire Science
The Time Lords' conflict with the Vampires cost trillions of lives on innumerable worlds back when they were still young. The vampires have recently been spotted in San Francisco once more. Some wish to coexist with humans and are conducting a grisly experiment to locate a new blood source. However, some would want to go out in a blaze of glory, and UNIT's efforts to confine them risk starting another terrible war.