After the death of Reggie's (14) and Don's (17) mother, the boys find themselves without parents. As their Aunt and Uncle get their home ready for them to move into, Reggie and Don are allowed to stay alone for a week in their mother's house. Shortly after their mom's funeral, Reggie starts to hear strange noises. He also begins to see things such as dead insects, dead rats and even dead people in his home. On top of this, his cat Tallman has mysteriously gone missing and Reggie keeps finding a strange, crust-like substance all over the house. Reggie tries to talk to Don about this but he is too busy with his girlfriend and his own life. With his brother only months away from turning 18, Reggie is terrified that Don is going to leave him alone with their Aunt and Uncle. He continues to experience strange events which eventually boil over when Reggie's best friend Angus spends the night. After disappearing when he goes to check out a noise emanating from Reggie's and Don's mother's bedroom (a room the brothers made a pact not to enter), they soon discover that what has taken him is scarier than they could have ever imagined. Reggie and Don must now band together if they are going to save Angus and themselves from the deadly Insect in their mother's bedroom.