The synopsis: Erin (Sharni Vinson) agrees to go with her boyfriend to his family reunion at their remote Missouri holiday house. Once there, the family is attacked and murdered one by one by unknown assailants wearing animal masks. Luckily, Erin happened to grow up on an Australian survivalist compound (NBD) and has intense martial arts and weaponry training, so she's able to fight back.
The twist: Erin's boyfriend and his brother arranged the entire scheme so that they could receive the majority of the family inheritance. Erin is not cool with this, naturally, and takes them all out in variously graphic ways (note: if you're really into smoothies and/or use a blender on a daily basis, I suggest avoiding this movie at all costs).
The amount of damage it'll do to your psyche: 🔪🔪🔪