“Come in and sit down, Mr. Ashleigh,” Quest invited.  “You know the Inspector.”

The Professor shook hands with French, and then, feeling that his appearance required some explanation, he took off his cap and looked at it ruefully.

“I am aware,” he said, “that this is not a becoming headgear, but I am lost—­absolutely lost without my servant.  If you would earn my undying gratitude, Mr. Quest, you would clear up the mystery about Craig and restore him to me.”

Quest was helping the Inspector to the whisky at the sideboard.  He paused to light a cigar before he replied.

“I very much fear, Professor,” he observed, “that you will never have Craig back again.”

The Professor sank wearily into an easy-chair.

“I will take a little whisky and one of your excellent cigars, Quest,” he said.  “I must ask you to bear with me if I seem upset.  After more than twenty years’ service from one whom I have always treated as a friend, this sudden separation, to a man of my age, is somewhat trying.  My small comforts are all interfered with.  The business of my every-day life is completely upset.  I do not allude, as you perceive, Mr. Quest, to the horrible suspicions you seem to have formed of Craig.  My own theory is that you have simply frightened him to death.”

“All the same,” the Inspector remarked thoughtfully, “some one who is still at large committed those murders and stole those jewels.  What is your theory about the jewels, Mr. Quest?”

“I haven’t had time to frame one yet,” the criminologist replied.  “You’ve been keeping me too busy looking after myself.  However,” he added, “it’s time something was done.”

He took a magnifying glass from his pocket and examined very closely the whole of the front of the safe.

“No sign of finger-prints,” he muttered.  “The person who opened it probably wore gloves.”

He fitted the combination and swung open the door.  He stood there, for a moment, speechless.  Something in his attitude attracted the Inspector’s attention.

“What is it, Mr. Quest?” he asked eagerly.

Quest drew a little breath.  Exactly facing him, in the spot where the jewels had been, was a small black box.  He brought it to the table and removed the lid.  Inside was a sheet of paper, which he quickly unfolded.  They all three read the few lines together:—­

    “Pitted against the inherited cunning of the ages, you have no
    chance.  I will take compassion upon you.  Look in the right-hand
    drawer of your desk.”

Underneath appeared the signature of the Hands.  Quest moved like a dream to his cabinet and pulled open the right-hand drawer.  He turned around and faced the other two men.  In his hand was Mrs. Rheinholdt’s necklace!

CHAPTER VIII

THE HOUSE OF MYSTERY

1.