CHAPTER I—THE TOLL IS EXACTED
CHAPTER II—"FRIENDS OF THE POOR"
CHAPTER III—ENGINEERING-CRIMINOLOGY
CHAPTER IV—THE CAR IN THE FOG
CHAPTER V—THE HAUNTED TREE
CHAPTER VI—THE FLAMING HAND
CHAPTER VII—SPIRIT CLUES
CHAPTER VIII—THE GIRL ON THE HORSE
CHAPTER IX—LUCY
CHAPTER X—CROSSED THEORIES
CHAPTER XI—TELEPHONE CALLS
CHAPTER XII—SATURDAY
CHAPTER XIII—A PUZZLING WARNING
CHAPTER XIV—THE INTRUDERS
CHAPTER XV—THE MASK OF DEATH
CHAPTER XVI—THE FATAL DANCE
CHAPTER XVII—AT THE DOORSTEP
CHAPTER XVIII—TRIANGULATION
CHAPTER XIX—FACE TO FACE
CHAPTER XX—THE INVISIBLE DETECTIVE
THE SECRET TOLL