Nancy's Mysterious Letter — Carolyn Keene

By mistake Nancy Drew receives a letter from England intended for an heiress, also named Nancy Drew. When Nancy undertakes a search for the missing young woman, it becomes obvious that a ruthless, dangerous man is determined to prevent her from finding the heiress or himself. Clues that Nancy unearths lead her to believe that the villainous Edgar Nixon plans to marry the heiress and then steal her inheritance.

During her investigation Nancy discovers that Nixon is engaged in a racket that involves many innocent, trusting persons. The thrilling hunt for Nixon and the heiress takes Nancy in and out of many perilous situations.

How the teen-age detective saves the British heiress from the sly, cunning schemer makes a highly intriguing story of mystery and suspense.