The Clue in the Diary by Carolyn Keene
Nancy and her friends, Georgie and Bess, returning from a village carnival, witness an explosion and fire in a beautiful estate. Fearing for its inhabitants, who might be left behind in the burning building, they rush to the rescue - and are suddenly confronted with a mystery that seems unsolvable. The first clue was an anonymous diary, but the entries in it were written in such hard-to-read handwriting that it was difficult to decipher.
Table of Content
Chapter 1 A Suspicious Stranger
Chapter 12 Incriminating Evidence