The robbery of the treasure in the tower proves to be an exciting challenge to Frank and Joe.

Nancy Drew travels to Peru to solve a mystery involving a long-lost treasure and a crossword clue carved into an ancient wooden plaque.

Ten brief cases allow the reader to match wits with ten-year-old crime-buster, Encyclopedia Brown, as he locates stolen jewels, solves a bank robbery, and more. Solutions are included at the back of the book.

The Hardy boys track down the saboteurs who kidnapped their father.

Frank and Joe solve a mystery involving the disappearance of a professor, a hot-tempered hermit, sabotage at the station, and the Honeycomb Caves.

Obstacles get in their way when Frank and Joe decide they want to buy a Chinese junk and open up a ferry service.

Attempts are made against Nancy's life when she accepts a case in Honolulu. She must decipher strange symbols written on a piece of paper in order to learn the mystery behind an estate inherited by her client.

Despite threats against her life, Nancy pursues the search for a clue in an antique stagecoach that may be of great value to the people of Francisville.

The Hardy boys dial a wrong number, get the Pentagon, and suddenly find themselves in a dangerous adventure involving national security.