Nancy Drew tackles a mystery professional detectives failed to solve--finding a valuable centuries-old message in a hollow oak tree in Illinois.

שם הספר
The clue in the crumbling wall - NANCY DREW MYSTERY STORIES #
Secrets can kill - 1 ; THE NANCY DREW FILES #
Deadly intent - 2 ; THE NANCY DREW FILES #
Murder on ice - 3 ; THE NANCY DREW FILES #
Smile and say murder - 4 ; THE NANCY DREW FILES #