Incantation

A mother addresses the camera directly, asking the audience to memorise a symbol and a chant to protect her daughter, and then tells the story of how, years earlier, she broke a religious taboo at a remote family shrine and brought a curse down on everyone connected to her.

Kevin Ko made the highest-grossing horror film in Taiwan's history, and its device is genuinely unsettling: the film keeps breaking the fourth wall to implicate the viewer, claiming that by watching and by learning the chant you are sharing the blessing, or the curse.

It is loosely inspired by a real Taiwanese case of a family who believed themselves possessed.

The found-footage structure jumps around in time, which some viewers find frustrating, and the ending's twist about what the audience has actually been doing is the reason it became a phenomenon.

It divides people sharply and it stays with the ones it works on.