Unobserved, Dale’s hand instinctively went to her bosom.  There it lay—­the motive—­the precious fragment of blue-print which she had torn from Fleming’s grasp but an instant before he was shot down.  Once Anderson found it in her possession the case was closed, the evidence against her overwhelming.  She could not destroy it—­it was the only clue to the Hidden Room and the truth that might clear Jack Bailey.  But, somehow, she must hide it—­get it out of her hands—­before Anderson’s third-degree methods broke her down or he insisted on a search of her person.  Her eyes roved wildly about the room, looking for a hiding place.

The rain of Anderson’s questions began anew.

“What papers did Fleming burn in that grate?” he asked abruptly, turning back to Dale.

“Papers!” she faltered.

“Papers!  The ashes are still there.”

Miss Cornelia made an unavailing interruption.

“Miss Ogden has said he didn’t come into this room.”

The detective smiled.

“I hold in my hand proof that he was in this room for some time,” he said coldly, displaying the half-burned cigarette he had taken from the ash tray a moment before.

“His cigarette—­with his monogram on it.”  He put the fragment of tobacco and paper carefully away in an envelope and marched over to the fireplace.  There he rummaged among the ashes for a moment, like a dog uncovering a bone.  He returned to the center of the room with a fragment of blackened blue paper fluttering between his fingers.

“A fragment of what is technically known as a blue-print,” he announced.  “What were you and Richard Fleming doing with a blue-print?” His eyes bored into Dale’s.

Dale hesitated—­shut her lips.

“Now think it over!” he warned.  “The truth will come out, sooner or later!  Better be frank now!”

If he only knew how I wanted to be—­he wouldn’t be so cruel, thought Dale wearily.  But I can’t—­I can’t!  Then her heart gave a throb of relief.  Jack had come back into the room—­Jack and Billy—­Jack would protect her!  But even as she thought of this her heart sank again.  Protect her, indeed!  Poor Jack!  He would find it hard enough to protect himself if once this terrible man with the cold smile and steely eyes started questioning him.  She looked up anxiously.

Bailey made his report breathlessly.

“Nothing in the house, sir.”

Billy’s impassive lips confirmed him.

“We go all over house—­nobody!”

Nobody—­nobody in the house!  And yet—­the mysterious ringing of the phone—­the groans Miss Cornelia had heard!  Were old wives’ tales and witches’ fables true after all?  Did a power—­merciless —­evil—­exists outside the barriers of the flesh—­blasting that trembling flesh with a cold breath from beyond the portals of the grave?  There seemed to be no other explanation.

“You men stay here!” said the detective.  “I want to ask you some questions.”  He doggedly returned to his third-degreeing of Dale.