An alien life form is accidentally pulled into Earth's gravity and discovered by three witches. Believing that the life form is evil, they cast a spell on it and lock it away in a lead tomb, almost ending its existence. Two hundred years later it finds itself free and waits to be found. Billy, Seth and Katie have been best friends their entire lives. With the end of seventh grade and summer vacation only two months away, Seth and Katie are trying to help their friend through a very difficult time; the death of his father. After yet another detention, an angry and frustrated Billy runs off to be by himself, and discovers a strange purple stone lying on a ledge. After sharing his great find with his friends, they soon realize that the orb is not just a pretty stone, but an entity that has begun to negatively alter their lives. Their adventure brings them into contact with a witch, whose ancestors originally discovered the orb. Billy, Seth and Katie come to the conclusion that in order to save their own lives, they must do whatever is necessary to free themselves of The Purple Orb.