"I wonder," he breathed.

Then, turning quickly on Theydon, he repeats the question.

"Are you quite sure they did not mention the discovery in this room of any object which could be regarded, even remotely, as a sign or symbol left by the murderer to show that his crime was an act of vengeance, or retaliation?"

Theydon hesitated. Unquestionably he was in a position of no ordinary difficulty. But his doubts were solved by an interruption that brought his heart into his mouth, because a thin, high-pitched voice came through the half-open door:

"Are you thinking of a small ivory skull, Mr. Forbes?"

CHAPTER VII
WHEREIN MR. FORBES EXPLAINS HIMSELF

Even the boldest may flinch when confronted with that which is apparently a manifestation of the supernatural. Theydon and Forbes were standing in a chamber of death. To the best of their belief they were alone in an otherwise empty flat, and those ominous words coming from some one unknown and unseen blanched their faces with terror.

But Theydon was a healthy and athletic young Englishman, and Forbes was of the rare order which combines a frame of exceptional physique with a mind accustomed to think imperially; two such men might be trusted to display real grit if surrounded by a horde of veritable spooks.

The door was thrown wide as they turned at the sound of the words, and Theydon recognized in a strange little figure—wearing a blue serge suit, a straw hat and brown boots—Furneaux, the man whom he had looked on as somewhat of a crank and visionary during their talk of the previous night.

"You?" he gasped, and the note of recognition was sharpened by a sudden sense of dismay, almost of alarm, because of the overwhelming knowledge that now all his scheming had collapsed, while the representatives of Scotland Yard would regard him as nothing more than a poor sort of trickster.