6CHAPTER II WHO IS THAT MAN?
27CHAPTER XXIII STRANGE PARTNERS
7CHAPTER III A TRAGIC EPISODE
28CHAPTER XXIV AND “PETERS” DROPS IN
8CHAPTER IV THE NEW VENTURE
29CHAPTER XXV A GHOST ON THE WIRE
9CHAPTER V A NEIGHBOR’S STORY
30CHAPTER XXVI WHO’S LETTER?
10CHAPTER VI THE END OF ONE TRAIL
31CHAPTER XXVII MYSTERY UPON MYSTERY
11CHAPTER VII INTO THE DEPTHS
32CHAPTER XXVIII THIS IS BRENT’S SUGGESTION
12CHAPTER VIII SHADOWS
33CHAPTER XXIX RIVERS IS DELIGHTED
13CHAPTER IX THE SIGN OF THE FOUR
34CHAPTER XXX THE THREADS UNRAVEL
14CHAPTER X THE WORK PROGRESSES
35CHAPTER XXXI AN EVENING OF DEDUCTIONS
15CHAPTER XI ALONE
36CHAPTER XXXII THE LETTER COMES BACK
16CHAPTER XII SIGNS ON THE MOUNTAIN
37CHAPTER XXXIII FACE TO FACE
17CHAPTER XIII THE STEADY GAZE
38CHAPTER XXXIV IT CAN’T RAIN FOREVER
18CHAPTER XIV THE APPARITION
39Analysis
19CHAPTER XV OUT OF THE PAST
40Reflection
20CHAPTER XVI SOMEBODY’S SON
41Memorable Quotes
21CHAPTER XVII BAFFLED