What are some famous plot twists in movies?

The 2012 horror film Sinister follows Ethan Hawke’s character, a true‑crime writer, as he moves into a new house. While renovating, he discovers a collection of old Super 8 home‑movie‑style recordings. These films depict gruesome murders and supernatural events, revealing a hidden, dangerous presence that threatens his family. The revelation of these forbidden recordings is the central, surprising element of the plot, and it propels the story into its climax.