House on the Cliff
Frank and Joe Hardy are investigating a mysterious old house high on the cliffs above Barmet Bay when they are frightened off by a scream. The boys return to the apparently haunted house when they make a connection between the place and a smuggling case their father is working on. When their father goes missing, they have to investigate the caves beneath the house and confront the smugglers.
Secret at the Old Mill
With two cases in tow, the Hardy boys look to Turner mill for clues. Determined to learn the secret of the old mill, Frank and Joe employ a clever ruse to gain entrance, only to find themselves trapped. How the young detectives extricate themselves from this dangerous situation and unravel mysteries will keep readers tense with suspense!