Dave and Brenda Brentwood are spending the summer with their Uncle Rob and Aunt Caryn in North Carolina. But the trip won't be all fun and games. There has been a monster trapped in a cave on the Brentwood property for over seventy years. After all those years, someone is trying to open up the cave. If their uncle can prevent the cave from being opened, they'll all have a nice quiet summer. If he can't then the family would have a terrible battle on their hands, and Brenda, twelve and Dave, eight, will truly find out what it means to be part of the family thing...