A couple of days ago, Dan Kukwa came over, bearing a copy of the Doctor Who story State of Decay. Despite some dated special effects and a few bouts of overacting, it was an entertaining ninety minutes, well directed with some genuinely creepy moments.
State of Decay has several alluring elements: it yanks Doctor Who from its science fiction trappings and into the realm of vampires, and there is a sense of ancient menace throughout the story. The Doctor and his companion Romana (also a Time Lord) sense that there's something familiar about all that they are facing. As the story plays out, it is revealed that millennia ago the Time Lords fought a race of giant vampires in a war so bloody, it sickened the Time Lords from direct violence. Eventually, the Vampires were hunted to extinction, but when the bodies were counted, one was missing: the most powerful vampire of all. And, of course, where the Doctor and Romana have landed, the Great Vampire sleeps, ready to wake to resume its war on life itself.
The echo of ancient wars is its own subgenre of science fiction and fantasy, and Doctor Who has played in this genre a number of times. In front of a backstory about ancient galactic battles, the Doctor and company discover elements that have survived millennia later, and which threaten to restart the terror. The Brain of Morbius, while channelling Frankenstein, gives several interesting details about Time Lord history, and describes a brutal struggle for power that decimated thousands of worlds. Pyramids of Mars describes the ancient war between the Osirians -- so brutal that it gave the Egyptian culture their pantheon of gods -- using a gothic manor, a handful of animated mummies, and one survivor: the evil Sutekh.
Other series do something similar: Quatermass and the Pit describes the invasion and cultural terraforming of Earth five-million years after the fact using the shell of an alien spaceship and a handful of skeletons. And how many stories are set in the aftermath of nuclear war, rather than during the war itself?
H.P. Lovecraft is the undisputed master (and quite possibly the father) of the genre. At the Mountains of Madness show the remnants of a civilization threatening explorers on Antarctica, while doing little to show the civilization in action. His stories are frightening not just because of what his monsters do, but what they could do.
Budget has a lot to do with why so many stories are about the remnants of wars rather than the wars themselves. Doctor Who has, with rare exceptions, had difficulty playing space opera, with galactic armies and giant space battles. If the show can hint at these battles with a forlorn general and a sense of gothic menace, then they save on special effects. More than that: if the galactic menace can be distilled into a single trapped or sleeping character and a handful of minions, then they can be beaten by a single hero and a handful of sidekicks. The Osirian war influenced the culture of Egypt and built pyramids on Mars as well as Earth, but the story of The Pyramids of Mars is all about the Doctor, Sarah Jane Smith and Lawrence Scarman fighting to keep Sutekh from breaking from his prison and relaunching his reign of destruction. It saves on actors' fees as well.
But as true gothic horror shows, through pictures as the classic Haunting (the 1963 version, please, and not the crappy remake) and The Sixth Sense, what is left unseen is often more frightening or exciting than what is seen. If you can imbue the story with a sense that a lot more menace exists behind what the characters currently see, then you'll give the story a compelling energy that space opera and monster-thrashes sometimes don't have. Monsters are more frightening when they're under the floorboards, and battles are bigger and bloodier when they echo through the vastness of time.