“Dale, watch that door and warn me if anyone is coming!” she commanded, indicating the door into the hall.  Dale obeyed, marveling silently at her aunt’s extraordinary force of character.  Most of Miss Cornelia’s contemporaries would have called for a quiet ambulance to take them to a sanatorium some hours ere this—­but Miss Cornelia was not merely, comparatively speaking, as fresh as a daisy; her manner bore every evidence of a firm intention to play Sherlock Holmes to the mysteries that surrounded her, in spite of Doctors, detectives, dubious noises, or even the Bat himself.

The last of the Van Gorder spinsters turned to Bailey now.

“Get some soot from that fireplace,” she ordered.  “Be quick.  Scrape it off with a knife or a piece of paper.  Anything.”

Bailey wondered and obeyed.  As he was engaged in his grimy task, Miss Cornelia got out a piece of writing paper from a drawer and placed it on the center table, with a lead pencil beside it.

Bailey emerged from the fireplace with a handful of sooty flakes.

“Is this all right?”

“Yes.  Now rub it on the handle of that bag.”  She indicated the little black bag in which Doctor Wells carried the usual paraphernalia of a country Doctor.

A private suspicion grew in Bailey’s mind as to whether Miss Cornelia’s fine but eccentric brain had not suffered too sorely under the shocks of the night.  But he did not dare disobey.  He blackened the handle of the Doctor’s bag with painstaking thoroughness and awaited further instructions.

“Somebody’s coming!” Dale whispered, warning from her post by the door.

Bailey quickly went to the fireplace and resumed his pretended labors with the fire.  Miss Cornelia moved away from the Doctor’s bag and spoke for the benefit of whoever might be coming.

“We all need sleep,” she began, as if ending a conversation with Dale, “and I think—­”

The door opened, admitting Billy.

“Doctor just go upstairs,” he said, and went out again leaving the door open.

A flash passed across Miss Cornelia’s face.  She stepped to the door.  She called.

“Doctor!  Oh, Doctor!”

“Yes?” answered the Doctor’s voice from the main staircase.  His steps clattered down the stairs—­he entered the room.  Perhaps he read something in Miss Cornelia’s manner that demanded an explanation of his action.  At any rate, he forestalled her, just as she was about to question him.

“I was about to look around above,” he said.  “I don’t like to leave if there is the possibility of some assassin still hidden in the house.”

“That is very considerate of you.  But we are well protected now.  And besides, why should this person remain in the house?  The murder is done, the police are here.”

“True,” he said.  “I only thought—­”

But a knocking at the terrace door interrupted him.  While the attention of the others was turned in that direction Dale, less cynical than her aunt, made a small plea to him and realized before she had finished with it that the Doctor too had his price.