“I thought there might be a spark there still, but I was mistaken,” he went on.  “He looked so natural—­and Mrs. Langmore looked natural, too, for the matter of that.  But both were stone dead.”

“What was the cause of death?”

“That is something of a mystery.  I have tried my best to get at the bottom of it, but I cannot, nor can my colleague, Doctor Soper.”

“Were the pair strangled, smothered, poisoned?” suggested the coroner.

“I have a theory that they were poisoned, but not in an ordinary way.  Neither Doctor Soper nor myself could find any traces of ordinary poison.”

“What is your theory?”

“Something was used to stupefy them, and so much was used that it killed them.”

“In that case the murder might have been unintentional?”

“Yes.  Somebody might have thought to stupefy Mr. Langmore and then rob him.  But the drug, being too powerful, or used too long, might have done its deadly work.  Then the crime may have been discovered by Mrs. Langmore and the murderer might have turned on her to conceal his first wrongdoing.”

“Hum.  Have you—­ahem! any idea of the nature of the poison?”

“No, excepting that it had a very powerful odor.  When I bent over Mr. Langmore I got several whiffs of it and it made me sick at the stomach.  But the odor was soon gone.”

“And you have no idea what the poison was?”

“No, nor has Doctor Soper.  It may be something new, or something little known.  Chemists are constantly discovering new things,” went on the young physician, bound to clear himself of any suspicion of ignorance concerning medical matters.

“You found no marks of violence, as if there had been a struggle?”

“The only marks I found were two scratches on the right arm of Mrs. Langmore, right above the wrist, and a scratch on Mr. Langmore’s left cheek.”

“Finger nail scratches?”

“Possibly, or else they may have been made by a ring or bracelet—­if there was a struggle.”

“Hum!  Have you anything else to tell, doctor?”

“I have not.  I am willing to tell all I know.”

There was another pause, as the young physician stepped back.  The coroner was about to call one of the women set to guard Margaret and the Langmore mansion, when he suddenly turned.

“Miss Langmore, you will please take the stand again,” he said, and the girl did so, throwing aside her veil.  “Are you in the habit of wearing finger rings and bracelets?”

It was a leading question and several gasped as they heard it.  Raymond started to rise up, but then sank back again.

“I do not wear bracelets,” answered Margaret.  “I have two rings.”

“What kind of rings are they?”

“One is a plain gold band.  It was my mother’s wedding ring.”  The girl’s voice sank low suddenly.  “The other is a diamond ring, as you can see,” and she held up her hand.