Private investigator Fenton Hardy enlists the aid of his teenage detective sons in a search for a missing man being sought by an insurance company. All leads to the sailor's whereabouts have petered out and the boys fly to Iceland, the man's native land, hoping to find a new clue. From the moment Frank and Joe arrive in Reykjavik, the capital city of Iceland, they are in constant danger. In the spine-chilling pursuit that follows, Frank and Joe uncover a diabolical espionage plot that threatens the life of a U.S. astronaut and NASA'S moon project.
While driving a motorboat around the Twin Lakes, Nancy and her friend Helen get caught in a dangerous storm. Luckily, they are rescued by another teenage girl in a rowboat. They soon learn that their rescuer is Laura Pendleton, whose mother has recently having passed away. Laura has come to meet up with her new guardians, but something isn't quite right about them. Nancy investigates the situation, and soon she stumbles upon a shocking surprise in the cellar of a bungalow
When Nancy is asked to find a professional dancer who disappeared several years before, the young detective becomes involved in a mystery reaching far beyond a missing-person's case. During Nancy's investigation at Heath Castle, she and her friends Bess and George realize that its crumbling walls contain a secret, but what is it? And who are their enemies that try to foil their every attempt to unravel the intricate puzzle? Danger lurks in a castle tower and throughout the vine-tangled grounds of the estate. The girls' gripping adventures culminate in a dramatic climax when Nancy exposes a sinister plot to defraud the dancer of her inheritance.
When the eerie performances of a life-size puppet begin to haunt the old Van Pelt estate, where an amateur acting group - The Footlighters - have their theater, Nancy Drew is called upon to unravel the baffling mystery. From the moment the detective and her friends Bess and George arrive at the mansion, the dancing puppet puzzle is further complicated by Tammi Whitlock, the Footlighters' temperamental leading lady, and Emmet Calhoun, a Shakespearean actor.Nancy's search of the mansion's dark, musty attic for clues to the weird mystery starts a frightening chain reaction. A phone call from a stranger with a witchlike, cackling voice warns her to "Get out " Next an encounter with two jewel theft suspects adds another perplexing angle to the puzzle. When Nancy finally sees the life-size puppet flitting across the moonlit lawn and chases it, she learns that someone with a sinister motive is determined to keep her form solving the case. Is it one of the Footlighters? Or is it an outsider?
Nancy Drew and her friend Bess discover that a rare and valuable Chinese vase has been stolen from the pottery shop of Dick Milton, a cousin of Bess. Dick had borrowed the vase from his Chinese friend, elderly Mr. Soong, and he is determined to repay Mr. Soong for the loss. He tells Nancy that if he can find "the leaning chimney," he will be on the track of a discovery which will solve his financial problems. Nancy finds the leaning chimney, but it only leads her into more puzzles. Can there be any connection between the vase theft - one of a number of similar crimes - and the strange disappearance of the pottery expert Eng Moy and his daughter Lei?
A masquerade party at the Hendricks' mansion quickly turns into a mystery when Nancy and her favorite date, Ned Nickerson, spy a stranger about to climb the rose trellis to the second story. Who is this enigmatic man in the black cloak and the exotic woman in the Javanese costume? Are they members of a gang of wily thieves who sneak into partied given by wealthy people and steal jewels and art treasures? And why is the owner of the black velvet hooded mask that Ned finds in the Hendricks' garden so desperate to get it back? To find the answers Nancy and her friend George devise a daring plan. The two girls switch identities George soon discovers that while it is exciting to play amateur detective it can be dangerous to masquerade as Nancy Drew.
A dying criminal confesses that his loot has been stored in the tower. Both towers of the looted mansion are searched in vain. It remains for the Hardy boys to make an astonishing discovery that clears up the mystery and clears the name of a friend's father.
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.
Not only is the local bank robbed, but two of the Hardy boys' pals mysteriously disappear after a masquerade party. Are the events related? How the Hardy boys use all their courage and skill to outwit the criminals provides an exciting climax to one of the most baffling mysteries the young detectives have ever encountered.
When the Hardy Boys eagerly agree to assist their friend Jack Dodd and his father in locating a family treasure, the two young detectives are unaware of the baffling complications that will arise. Deadly road traps, aerial ambush, a spider man and a suspect who carries a menacing cane harass the young detectives as they seek the triple solution to this perplexing and exciting mystery.