The Cairn's life seems to be a harmonic family: The father Brad (Sam Rockwell) works as a stockbroker, his wife Abby (Vera Farmiga) takes care of their common new-born daughter Lily (Kolb and Vill), and the nine-year-old Joshua (Jacob Kogan) is high-talented. But the appearances are deceptive. Joshua becomes gradually jealous that his parents give the baby more attention than him. As a result, he begins to terrorize his family.