Uninvited guests, haunted houses, secret passageways: It’s just another day in the life of America’s favorite detective Nancy Drew! In this adventure, Nancy must unravel the mystery behind a string of thefts with a sinister stone mansion at the center. Can Nancy discover the secret before it’s too late? This is a reprint of the 1930 first edition of Nancy Drew Mystery Stories: The Hidden Staircase, without cuts or censorship, as originally written by Mildred Benson under the pen name Carolyn Keene.