10 More Horror Movie Twists That Were Hiding In Plain Sight

10. You're Next

You all know how it is. You're trying to enjoy a family get-together when a bunch of masked vigilantes barge in and attack you with crossbows. Such is the premise of Adam Wingard's You're Next. 

About an hour in, it's revealed that one of the family members, Felix, orchestrated the whole thing with his girlfriend, Zee, and his brother, Crispian, hoping to claim their parents' inheritance. Although this trio seemed innocent at first, their true motives were repeatedly implied.

When nobody can get phone service, Felix points out the killers are using a mobile blocker "which you can get on the internet for $30". The fact Felix knows the invaders are using jammers and how much they cost should've made him a suspect straight away.

Felix is also the one who encourages the others to sprint out of the house, knowing the entrance is surrounded by razor-sharp wire. And after his sister is garrotted to death, the family is discouraged from leaving, making it easier for them to be hunted down.

However, the one thing stopping the victims from being picked off easily is Crispian's girlfriend, Erin. While everyone else is helplessly screaming, Erin takes charge, setting up booby traps and single-handedly slaughtering the invaders.

On the surface, Felix and Crispian seem surprised by Erin's diligence. But on a rewatch, it's obvious they're scared, since she's jeopardising their operation.