The adventures of the four Alden children as they investigate a mystery that took place in the yellow house on Surprise Island many years before.

While trying to help a friend out of a difficulty, teenage detective Nancy Drew has a perilous experience in and around a deserted bungalow.

While searching for the guard end of a broken saber that will solve one mystery, the Hardy brothers become involved with a gang of bank robbers.

While living on a moon base with fellow lunarnauts, Dashiell Gibson investigates the murder of one of the moon's most prominent doctors.

Thea Stilton returns to her old school, Mouseford Academy, to teach a course in adventure journalism, and investigates a mystery involving a strange inscription and a missing person along with five female students.

Nancy and her friends establish headquarters in a seaside yacht club to investigate strange happenings in a book store and the disappearance of a marble statue.

The Hardy brothers embark on a freighter trip under mysterious circumstances and find themselves involved with a smuggling ring.

Dink Duncan and his two friends investigate the apparent kidnapping of famous mystery author Wallis Wallace.