“You miss the point,” he said, still good-naturedly.  “The thing that is funny, to me, is that you insist on remaining here, under the circumstances.  I should think nothing would keep you.”

“You are mistaken.  Everything that occurs only confirms my resolution to stay until the mystery is cleared.”

“I have a message for you, Miss Innes,” he said, rising at last.  “Mrs. Armstrong asked me to thank you for your kindness to Louise, whose whim, occurring at the time it did, put her to great inconvenience.  Also—­and this is a delicate matter—­she asked me to appeal to your natural sympathy for her, at this time, and to ask you if you will not reconsider your decision about the house.  Sunnyside is her home; she loves it dearly, and just now she wishes to retire here for quiet and peace.”

“She must have had a change of heart,” I said, ungraciously enough.  “Louise told me her mother despised the place.  Besides, this is no place for quiet and peace just now.  Anyhow, doctor, while I don’t care to force an issue, I shall certainly remain here, for a time at least.”

“For how long?” he asked.

“My lease is for six months.  I shall stay until some explanation is found for certain things.  My own family is implicated now, and I shall do everything to clear the mystery of Arnold Armstrong’s murder.”

The doctor stood looking down, slapping his gloves thoughtfully against the palm of a well-looked-after hand.

“You say there have been intruders in the house?” he asked.  “You are sure of that, Miss Innes?”

“Certain.”

“In what part?”

“In the east wing.”

“Can you tell me when these intrusions occurred, and what the purpose seemed to be?  Was it robbery?”

“No,” I said decidedly.  “As to time, once on Friday night a week ago, again the following night, when Arnold Armstrong was murdered, and again last Friday night.”

The doctor looked serious.  He seemed to be debating some question in his mind, and to reach a decision.

“Miss Innes,” he said, “I am in a peculiar position; I understand your attitude, of course; but—­do you think you are wise?  Ever since you have come here there have been hostile demonstrations against you and your family.  I’m not a croaker, but—­take a warning.  Leave before anything occurs that will cause you a lifelong regret.”

“I am willing to take the responsibility,” I said coldly.

I think he gave me up then as a poor proposition.  He asked to be shown where Arnold Armstrong’s body had been found, and I took him there.  He scrutinized the whole place carefully, examining the stairs and the lock.  When he had taken a formal farewell I was confident of one thing.  Doctor Walker would do anything he could to get me away from Sunnyside.

CHAPTER XXI

FOURTEEN ELM STREET