Before 1950, the monsters from outer space were pretty much stuck in Buck Rogers serials. But then in 1951, Howard Hawks acting as producer (With Christian Nyby directing), made The Thing, a movie about scientists at an Arctic research station who dig up the body of an alien creature and accidentally thaw it out, with predictably dreadful results.

After that, there was no keeping away the alien beings. They proliferated in such low-budget genre greats as The Creature From the Black Lagoon, released in 1958, not a classic by any standard, but vastly imitated over the years – and almost certainly on of the wellsprings of inspiration for Alien. Then there is Forbidden Planet (1956), and Don Siegel's Invasion of the Body Snatchers (1956), an absolute classic that still holds up today.

James Cameron, who would grow up to direct The Terminator, Aliens and Terminator 2, came from Kapuskasing, Ontario, and was one of those kids fascinated with schlock science fiction, monster and horror movies. "People have certain universal responses to things, and I think a lot of so-called 'schlock' films were entirely reliant on those responses for success because they had no cast or they had a bad script. They had no choice but to create a response."

Nobody understood that need more completely, or exercised it more effectively than John Carpenter, who wrote and directed Halloween. By turnin ghte most successful independent film ever made to that time (it cost $320,000 and grossed $80 million worldwide), and the precursor of dozens of imitations – including the Friday the 13th series.

Carpenter points out that what makes people so uncomfortable about most types of horror films, and what keeps them relegated to the back alleys of American filmmaking, is the way they insist on making us explore the darkness in ourselves. No matter where the evil in monster movies seems to appear form, it actually springs from inside all of us. "That's something no one wants to look at," Carpenter maintains. "We don't want to look at ourselves that way.'