Summer, 1993 – a group of young guerrilla filmmakers spend four weeks making Horror Movie, a notorious, disturbing, art-house horror film.

The weird part? Only three of the film's scenes were ever released to the public. Steeped in mystery and tragedy, the film has taken on a mythic renown.

Decades later, a big budget reboot is in the works, and Hollywood turns to the only surviving cast member – the man who played ‘the Thin Kid’, the masked teen at the centre of it all. He remembers all too well the secrets buried within the original screenplay, the bizarre events of the filming, and the crossed lines on set.

Caught in a nightmare of masks and appearances, facile Hollywood personalities and fan conventions, the Thin Kid spins a tale of past and present, scripts and reality, and what the camera lets us see. But at what cost do we revisit our demons?

After all these years, the monster the world never saw will finally be heard.