“And Mrs. Armstrong—­is she also ill?”

“She is with Miss Louise and can not be disturbed.”

“Tell her it is Miss Innes, and that it is a matter of the greatest importance.”

“It would be of no use, Miss Innes.  My orders are positive.”

At that moment a heavy step sounded on the stairs.  Past the maid’s white-strapped shoulder I could see a familiar thatch of gray hair, and in a moment I was face to face with Doctor Stewart.  He was very grave, and his customary geniality was tinged with restraint.

“You are the very woman I want to see,” he said promptly.  “Send away your trap, and let me drive you home.  What is this about your nephew?”

“He has disappeared, doctor.  Not only that, but there is every evidence that he has been either abducted, or—­” I could not finish.  The doctor helped me into his capacious buggy in silence.  Until we had got a little distance he did not speak; then he turned and looked at me.

“Now tell me about it,” he said.  He heard me through without speaking.

“And you think Louise knows something?” he said when I had finished.  “I don’t—­in fact, I am sure of it.  The best evidence of it is this:  she asked me if he had been heard from, or if anything had been learned.  She won’t allow Walker in the room, and she made me promise to see you and tell you this:  don’t give up the search for him.  Find him, and find him soon.  He is living.”

“Well,” I said, “if she knows that, she knows more.  She is a very cruel and ungrateful girl.”

“She is a very sick girl,” he said gravely.  “Neither you nor I can judge her until we know everything.  Both she and her mother are ghosts of their former selves.  Under all this, these two sudden deaths, this bank robbery, the invasions at Sunnyside and Halsey’s disappearance, there is some mystery that, mark my words, will come out some day.  And when it does, we shall find Louise Armstrong a victim.”

I had not noticed where we were going, but now I saw we were beside the railroad, and from a knot of men standing beside the track I divined that it was here the car had been found.  The siding, however, was empty.  Except a few bits of splintered wood on the ground, there was no sign of the accident.

“Where is the freight car that was rammed?” the doctor asked a bystander.

“It was taken away at daylight, when the train was moved.”

There was nothing to be gained.  He pointed out the house on the embankment where the old lady and her daughter had heard the crash and seen two figures beside the car.  Then we drove slowly home.  I had the doctor put me down at the gate, and I walked to the house—­past the lodge where we had found Louise, and, later, poor Thomas; up the drive where I had seen a man watching the lodge and where, later, Rosie had been frightened; past the east entrance, where so short a time before the most obstinate effort had been made to enter the house, and where, that night two weeks ago, Liddy and I had seen the strange woman.  Not far from the west wing lay the blackened ruins of the stables.  I felt like a ruin myself, as I paused on the broad veranda before I entered the house.