A million dollars’ worth of gold bullion has been stolen from the Wakefield Mint under strange circumstances. Mr. hardy is asked to investigate but before long his life is threatened, and he asks Frank and Joe to help him. The boys fly to Zurich, Switzerland, hoping to get information at the Swiss Gold Syndicate and to find the man who has stolen a valuable ancient gold figurine from a New York museum. Their search on both counts seems futile as they return to the United States where they uncover clues that lead them to an adventure in the Yucatán jungle. But the Hardy’s travels lead to nothing but new doubts and nagging suspicions. And now their lives are in danger.

First valuable antique weather vanes are stolen in Pennsylvania Dutch Country and Frank and Joe are hired to catch the thieves. Meanwhile, their father is asked to find a missing Navy employee and a top-secret government document. What is the connection between the missing weather vanes and the Pentagon spy? The final chapters of this thrilling mystery uncover a stunning revelation!

The Hardy Boys series, first published in 1927, has sold more than 70 million copies! Now with a brand-new look, this is an edition that collectors won't want to miss! In The Missing Chums, the fourth book in the incredibly popular, long-running series, Frank and Joe Hardy must save their friends from a rogue group of kidnappers. A special treat for Hardy Boys fans and any reader who's new to the series.

Frank and Joe Hardy become involved in a case affecting national security when Joe dials a wrong telephone number and gets the Pentagon. Two words— “Bombay Boomerang”— that the boys hear before the line goes dead plunge them into a whirlpool of danger and intrigue. At the same time, Frank and Joe must save their father from a murderous gang stealing mercury shipments in the Baltimore harbor. With clues linking the mercury thefts to the top secret Super S missile mysteriously stolen from a government arsenal. In a race against time, the three Hardys foil a diabolical scheme to create widespread havoc in the United States.

Danger is the name of the game when the Hardys agree to help their pen pal from Greece, Evan Pandropolos, search for a priceless, ancient Greek helmet. Years ago, Evan’s uncle had loaned it to Hollywood movie company for use in a silent motion picture, but the treasured helmet had been lost. Picking up foes along the way, the young detectives unearth clues that keep them constantly on the move—from their Greek college campus to California and finally to Greece.

A series of museum thefts launch the Hardy Boys on this baffling mystery. Rare collections of ancient pirate treasure are being stolen, so Frank and Joe are asked to stake out the Black Parrot, a suspicious freighter docked in Bayport Harbor. This whirlwind chase after a self-styled pirate king in the Caribbean stronghold of the Empire of the Twisted Claw makes a gripping tale of suspense and high adventure.

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.

Together in this one book are two of the Hardy Boys’ oldest mysteries that began the classic mystery series of the sleuthing siblings. In The Tower Treasure, the Hardy boys' summer is ruined by a red-haired robber striking all over town. No robbery is more devastating than of Tower Mansion, home to one of the wealthiest families around. To prove the mansion’s caretaker is innocent, the Hardy boys will have to solve the mystery of the stolen jewels before time runs out. In The House on the Cliff, Frank and Joe are asked to help out their famous private detective father on his latest drug smuggling case, which sends them to an old house on a cliff to serve as lookouts. But when cries for help lure the boys inside the house, they realize they could be in more danger than they thought.

Valuable electronic parts containing platinum are being stolen from shipments made by Stanwide Mining Equipment’s cargo planes, and Frank and Joe are called upon to assist their world-renowned detective father solve the baffling case. While posing as Stanwide employees, the boys look into the truth behind the chief pilot’s death at sea. The puzzling trail of clues leads the young sleuths to an uninhabited Caribbean island, but the final, and most startling, discovery is made in the boys’ home town of Bayport.

Frank and Joe Hardy suspect that their best friend Chet Morton is the victim of a summer school swindle and offer to help get his money back. While probing a baffling burglary at the Seneca Indian Reservation in New York State they investigate Zoar College located nearby. A startling connection between the Zoar College swindle and the theft of the Seneca’s gold tribal relic Spoon Mouth propels the teenage sleuths into a series of perplexing and dangerous situations.