Footage of a door opening and closing of its own accord is the first sign that something is terribly wrong in the home.

Micah doesn’t take his role seriously, brazenly goading the spirit (“Is that all you got?”), while Katie desperately tries to prevent him making a bad situation worse.

As the visitations become more intense, Micah invites a psychic (Mark Fredrichs) through the front door.

The visitor leaves quick-smart, sensing that evil has taken root in the house and will stop at nothing until it has consumed Katie.

“You can’t run from this, it will follow you,” he professes sombrely.

Paranormal Activity almost lives up to the extraordinary hype from across the Atlantic, effectively tapping into universal fears.

Featherston and Sloat are compelling, the latter grating on our nerves as much as Katie’s as he foolishly introduces a Ouija board to the house, then rows with his frazzled girlfriend, cattily telling her to “go hang out with your friend upstairs!”

Physical manifestations of the malevolent spirit start with a light turning on in the middle of the night, or a shadow moving across the bedroom door.

As the film moves into the shocking final act, Peli pulls out all of the stops to have us biting our nails down to the cuticle.

If you thought you were too old to be afraid of the dark, think again.