em: An impossible door; the
window equally out of the question; the substitution of the coals for
the coin.

"It is very simple. The outside agency unfeasible, we must look within.
There is but one conclusion----"

"And that?" interrupted Raikes.

"An accessory."

"Ah!" cried Raikes, "unthinkable!"

"Not at all," replied Gratz; "there was an accessory--yourself!"

At this announcement Raikes seemed about to collapse into his original
helplessness. The facts of his losses were extraordinary enough, but
this was too much.

But Gratz hurried on, explained the unconscious visits of his astounded
hearer to the cellar, and all that followed.

"Then," exclaimed Raikes, when he had concluded, "I have been the victim
of hypnotic suggestion."

"Precisely!" replied Gratz. "The story was merely the medium of
transmission, and through this weird conduit the story-teller conveyed
his instructions to your subconsciousness."

"But," demanded Raikes, "why this substitution of coals? It strikes me
that a scheme so clever as all this would scarcely be jeopardized by
such an absurdity."

"That contingency," answered Gratz, "was never intended. In your
condition of mind, having discharged the coin upon the floor of the bin,
a mental idiosyncrasy of years insisted upon recognition.

"In some inexplicable way you retained enough of your mental identity to
preserve some manifestation of the law of equivalents. In other words,
having parted with something, you demanded something in return.

"With as much deliberation, therefore, as you manifested in contributing
to your loss, you attempted to reimburse yourself by filling the bag
with coal.

"In some occult way you assured yourself that you were engaged in a
transaction where one commodity took the place of another.

"To this freak of mentality the idea of the pebbles in the story being
substituted for the diamonds contributed; and what was intended by the
narrator as a consistency of detail, to be explained later on, made an
unforeseen appeal to your native cupidity and provided me with a very
satisfactory clue.

"Moreover, the narrator assisted himself by allowing you to contemplate
some brilliants--a sapphire, a diamond.

"In such demonstrations a centralizing object is an almost indispensable
adjunct; and putting the two together, the stories, the brilliants, it
is not difficult to see that you have received your instructions in the
manner indicated, and obeyed them w