Fenton Hardy, the famous private detective and father of the Hardy Boys, asks his sons to help him with his latest case involving a criminal named Snattman and the smuggling of stolen drugs. Mr. Hardy directs Frank and Joe to the house on the cliff, whose location near Barmet Bay offers an excellent vantage point to watch for smugglers. The Hardys are tricked into the house by cries for help, and are trapped in the attic! How will the Hardy Boys ever get themselves out of this mess?