red at the bag with a
superstitious terror.

"But," continued Gratz, "what seems so incredible to you is merely the
logical outcome of a cunningly established sequence," and the speaker
shot an incredibly quick glance at the silent figure in the adjoining
room.

"Now attend me closely.

"During the last few evenings you have heard some very curious
narratives."

Raikes nodded with gloomy corroboration.

"A series of well-arranged events have introduced a startling
episode--the substitution of pebbles for diamonds."

Again Raikes nodded.

"At this point in the narrative the first instalment concludes. Am I
right?"

"Yes," answered Raikes.

"Then," continued Gratz, "you went directly to your room; you retired.
In the morning you are prompted, with more than your usual eagerness, to
open your private safe."

"Right!" exclaimed Raikes in indorsement of this relentless resume.

"You find the locks undisturbed; the contents apparently as you left
them on retiring. Some difference in the conformity of one of the bags
urges a nearer examination. You discover that this indicates a
difference in the contents. You grasp it; it comes away in your hands
with startling lightness. You discharge its deposit upon the table--a
shower of coals follows."

"Yes, yes!" stammered Raikes with impatient eagerness.

"Well, you are convinced, by an examination of the fastenings of the
door, an inspection of the window, that no human being could have
effected an entrance from either direction.

"The next evening is a repetition of the history of the night before.

"The strange Indian narrative, another gem to examine--an additional
loss on the succeeding morning."

Raikes nodded savagely.

"On the following night the same unhappy series of events occur,
followed by the loss of the third bag."

"But why all this again?" inquired Raikes.

"That concerns me," exclaimed the detective with another rapid glance at
the undemonstrative figure in the next room. "You must follow my
instructions or you will conclude as badly as you have begun. Now,"
continued Gratz, "it is incredible to me that, with the astuteness with
which you are credited, that having such a good standpoint to begin
with, you did not proceed upon that basis."

"I?" questioned the astonished Raikes. "What standpoint had I?"

"Elimination," replied Gratz.

"Several puzzling possibilities were retired permanently.

"Recall the details as we have enumerated th