Casey, a rebellious teenage girl, is travelling with her mother Elaine, her stepfather Jonah, and her two younger half-siblings, Miranda and Paulie, to spend the New Year holiday at the secluded home of Elaine's sister, Chloe. Chloe, her husband Robbie, and their two young children, Nicky and Leah, welcome their visitors. Shortly after arriving, Paulie steps near some bushes and begins vomiting, which the adults believe is due to travel sickness or just some random bug as is usual for kids to catch.