is a
false radiator, the real flue is on the other side of the room.

"The rear of this small safe backs up against nearly two feet of solid
brickwork.

"Exactly behind that is a room occupied by one no more burglarious than
a dressmaker's apprentice."

"Thank you," replied Gratz. "Your information is helpful, but I am never
satisfied to rely upon description when investigation is possible.

"Whatever deductions I make from this examination I do not want
disturbed, so all the doubts they dissipate are not likely to intrude
upon my calculations again."

After a few further taps, in which Raikes could see no better purpose
than to retire from an embarrassing position with some show of satisfied
motive, Gratz directed that the bags be returned.

For the next few minutes he busied himself with the locks, upon which he
experimented with the extraordinary keys which Raikes had given him. He
shot the bolts backward and forward; noted the stout bar and the
precautions for keeping it in place, and then resumed the seat near the
table.

After a few moments he said:

"Tell me what has occurred to you between sunrise and sunset during the
last three days."

Raikes recounted his usual round of petty detail, which had no possible
bearing upon the problem.

When he had concluded this meager resume, Gratz continued:

"Now tell me about the nights."

Raikes complied with a statement of his careful precautions; the watch
of his sister upon the doorway during his absence, and his visits to the
room of the Sepoy.

"The Sepoy?" inquired Gratz. "Why do you call him that?"

"On account of his swarthy complexion, his bright eyes, and his general
alien aspect," replied Robert.

"Describe him to me as carefully as you can," said Gratz.

When Robert had concluded his brief delineation, Raikes hastened to
inquire: "Why do you ask about him so particularly? He could no more
enter my room, under the conditions I have described to you, than you
could."

"I realize that," admitted the detective, "but I gather from what you
have just said that you visit this Sepoy, as you call him, with some
degree of regularity. May I ask if you have business transactions with
him?"

"I have not," replied Raikes.

Then, in response to the unchanging look of inquiry in the countenance
of the detective, he added:

"The Sepoy has been telling me an extraordinary story. It has been too
elaborate to confine to one sitting, and my purpose in re-v