The story of Paranormal Activity’s journey to the big screen is as intriguing as the movie itself. Made back in 2007, it debuted at the Screamfest Horror Film Festival in Los Angeles, before being passed from studio to studio without anyone really knowing what to do with it.

It finally fell to Paramount Pictures, who intended to take this US$15,000 ghost story, shot on a domestic video camera in the director’s own house, and remake it into a proper studio picture. However, after screening the original version for potential writers, the film’s power to scare became immediately apparent and all remake plans were scrapped.

Following a hugely successful online marketing campaign, the film opened nationwide at Halloween and Paranormal Activity has since set the record for the most profitable independent film of all time, grossing over US$100 million in the US alone.

Katie (Katie Featherston) is a young woman living in San Diego, who has suffered most of her life from what she describes as some form of haunting. Her supportive boyfriend Micah (Micah Sloat) is only too happy to investigate, and sets up a video camera in their bedroom to capture any paranormal activity that may occur while they sleep. What begins as a few unexplained noises and slamming doors slowly escalates into a terrifying ordeal, all documented by the couple themselves.

Using a similar format to The Blair Witch Project – and seemingly set to enjoy the same degree of international success – Paranormal Activity uses no crew or professional actors, instead having the cast members film themselves, with only vague narrative outlines, around which they improvised their own dialogue. The result is an entirely naturalistic, believable and most importantly scary little film.

It should be pointed out that while the film is garnering impressive word-of-mouth wherever it plays, Paranormal Activity is not the scariest film you’ll ever see, or possibly even this year. It’s rampant advance word, which has been the key to its success, may also prove the key to its undoing if the filmmakers and studios are not careful. Do not go into Paranormal Activity expecting an unparalleled horror experience, as most likely you’ll leave the theatre disappointed.

The film is creepy and effective, not least because it uses atmosphere and human reactions to build tension, playing upon our primal fears of the dark and the things that go bump in the night. One of the film’s most disturbing images is of a major character standing still, doing absolutely nothing, and does for bedroom doors what The Ring did for televisions.

The film features little in the way of special effects or make-up and more than anything, this micro-budget blockbuster proves how unnecessary and inconsequential those elements truly are when used in place of a simple story that captures the imagination of its audience. Bear these things in mind and it’s possible you’ll be sleeping with the lights on for some time to come.