The Hidden Staircase, published in 1930, was the second in a long line of the acclaimed Nancy Drew mysteries. The author is the pseudonymous Carolyn Keene, but this and other early novels in the series were written by Mildred Wirt Benson, who said The Hidden Staircase was her favorite of them all.

In this book, Nancy, the daughter of prominent attorney Carson Drew, is visited one evening by Nathan Gombet, a sinister man who claims that Carson Drew swindled him out of money for a property.

Nancy gets rid of Gombet with difficulty. Soon after, she is drawn into the case of the Turnbull sisters, unmarried women living alone in their old family mansion, Cliffwood.

The sisters claim that their house is haunted, but it quickly becomes clear that something more is afoot: valuable heirlooms of the Turnbull family mysteriously vanish. Nancy, sure that ghosts are out of the question, stays with the sisters to unravel the mystery. She is certain that there must be some secret entrance to the old house, but she cannot find it.

In the meantime, Carson Drew is mysteriously detained in a trip out of town on business. Nancy does not hear from him, and she worries that something may have happened to him.

Nathan Gombet has tried to purchase the sisters' house at far below its value. Nancy is sure that Nathan is behind the uncanny occurrences. She finds that he also has to do with the disappearance of her father.

The Nancy Drew mysteries debuted in a fast-changing America, where women were rapidly discarding traditional roles and asserting themselves. Nancy models this new American woman: strong-willed, intelligent, indomitable, educated, and sharp-minded.

In the nearly 100 years since their debut, the Nancy Drew mysteries have become an integral part of the American feminine mythos.

The evergreen popularity of the Nancy Drew series led to many film and television adaptations. Today, nearly a century after their launch, the Nancy Drew books remain classics of young adult fiction.