Insidious represents a collaboration of the Saw creators and the producers of Paranormal Activity, and the result is one of the strongest horror pictures in years. While all signs seemed to suggest that a clunker was imminent – Insidious is a PG-13 horror film about a possessed kid, after all – director James Wan has defied the odds, overcoming a derivative narrative and the limitations of a PG-13 rating to craft a properly chilling and thoroughly riveting horror experience. For those who enjoy watching scary movies, you’re in for a treat with Insidious.

As the film kicks off, school teacher Josh (Wilson) and his aspiring musician wife Renai (Byrne) move into a spacious new house with their three kids seeking a fresh start. However, trouble arises for the family when young Dalton (Simpkins) falls into a mysterious coma that the doctors are unable to explain. Soon afterwards, Renai becomes overwhelmed by unexplainable occurrences and terrifying visions of strangers lurking around their residence. Though Josh tries to be supportive by agreeing to Renai’s plea for a move, similar situations immediately begin to haunt their next house. Bewildered by the extraordinary state of affairs, Renai seeks help from spiritual expert Elise (Shaye) and her pair of technicians (Sampson, Whannell).

Essentially Poltergeist meets Paranormal ActivityInsidious gets practically everything right – the atmosphere, soundtrack, photography, direction, script and acting are all top notch, combining to create the most skin-crawling mainstream horror movies of 2011. James Wan did not have big bucks on his side here (reports place the budget at $1.5 million), but the limited scope works to the picture’s benefit as the “less is more” approach heightens tension. While there are a few lazy jump scares, they are often effective thanks to the stylish photography and Wan’s sharp eye for sinister images. Most importantly, Insidious is not hindered by its PG-13 rating – it never seems neutered because Wan recognised the importance of atmosphere and story, two elements of which are vital for creating a successful horror movie. Wan and writer Leigh Whannell also paid attention to the story’s human element, which reinforces the inherent terror of the situations that the protagonists become entangled in. And towards the climax, the production transforms into a bit of a macabre funhouse, with tension being released through a smattering of campy humour.

Whannell (who also stars as a paranormal investigator) wrote the script for Insidious with a list of horror clichés beside him to ensure that he avoided as many of them as possible, and the results are sublime. It’s easy to respect the characters and believe in them, because they seem like realistic, intelligent human beings rather than contrived script puppets. For instance, the old cliché of “Why don’t they just leave the house?” is addressed – after one particularly bad night, Renai and Josh actually move. Then when the paranormal occurrences persist, they consult experts. And Josh’s reluctance to believe in the paranormal theories seems natural rather than contrived. While Wan’s script borrows structural elements from movies like The Amityville HorrorPoltergeist and The Exorcist (just to name a few), originality in the horror genre is not always important. Rather, a horror movie just needs to scare viewers with a genuinely well-made excursion into pure terror. Insidious does just that, and does it remarkably well despite a few weak spots (for instance, one shot of the demon crawling along a wall towards the end looks pretty lousy). This all culminates with a final scene that transcends convention in a terrifying fashion.

Run-of-the-mill horror often pictures falter on the acting front, but Insidious excels with a cast that’s confidently above average. Front and centre is the Australian-born Rose Byrne (Get Him to the GreekKnowing), whose nuanced performance as Renai is a standout. Whenever her character is scared, Rose sells it effortlessly, all the while emanating movie star charisma to allow us to be invested in her plight. Alongside her, as Josh, Patrick Wilson (WatchmenHard Candy) is constantly believable and engaging. In the supporting cast, meanwhile, Angus Sampson and Leigh Whannell appear as Ghostbuster types who investigate the paranormal occurrences, and they did a great job of selling both comedy and intensity. Rounding out the main players is Lin Shaye as the clairvoyant with experience in the field of the paranormal. Shaye’s performance gives the material a tremendous amount of welcome gravitas.

Insidious can be likened to a funhouse ride in a theme park, as the film takes its audience on a tour full of creepy images and spooky things which pop out at them, and the terror refuses to alleviate until the ride is over. It also shares similarities with Sam Raimi’s style of terror, most notably Drag Me to Hell where the thrills and chills are created through simple images, a bombastic soundtrack and a cats-walking-on-instruments score.