The Mystery of Lilac Inn, first published in 1930, is the fourth in the famed Nancy Drew mystery series.

In this thrilling novel, Nancy follows the fate of a set of extremely valuable jewels of which her impoverished friend Emily Crandall has come into possession. Emily’s guardian, Jane Willoughby, has taken on the task of fetching the jewels from a safe-deposit box in a nearby town. While coming home, Mrs. Willoughby and her friend Mrs. Potter stop at the picturesque old Lilac Inn for lunch. Mrs. Willoughby has the jewels in her handbag. When attention is distracted by a car crash outside, Mrs. Willoughby comes back to the table to find that her handbag—and the jewels—are missing.

Aided by her father, the distinguished criminal justice attorney Carson Drew, Nancy steps in to investigate. She follows numerous baffling clues that cast suspicion upon a number of people, including Mrs. Willoughby, Mrs. Potter, the restaurant staff, and Mary Mason, a sinister young woman who had unsuccessfully applied for a position as housekeeper for the Drew household. Finally Nancy tracks down the culprits after a dangerous chase.

The Mystery of Lilac Inn was published under the pseudonym Carolyn Keene, although it was written by Mildred Wirt Benson, the author of several other early Nancy Drew novels and creator of the adventurous title character.

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 100 years after their launch, the Nancy Drew books remain classics of young adult fiction.