“Who is it?” he called imperiously, and took a half dozen rapid strides toward the foot of the staircase.  Then I heard him mutter something; there was the crash of a falling body, the slam of the outer door, and, for an instant, quiet.  I screamed, I think.  Then I remember turning on the lights and finding Halsey, white with fury, trying to untangle himself from something warm and fleecy.  He had cut his forehead a little on the lowest step of the stairs, and he was rather a ghastly sight.

He flung the white object at me, and, jerking open the outer door, raced into the darkness.

Gertrude had come on hearing the noise, and now we stood, staring at each other over—­of all things on earth—­a white silk and wool blanket, exquisitely fine!  It was the most unghostly thing in the world, with its lavender border and its faint scent.  Gertrude was the first to speak.

“Somebody—­had it?” she asked.

“Yes.  Halsey tried to stop whoever it was and fell.  Gertrude, that blanket is not mine.  I have never seen before.”

She held it up and looked at it:  then she went to the door on to the veranda and threw it open.  Perhaps a hundred feet from the house were two figures, that moved slowly toward us as we looked.

When they came within range of the light, I recognized Halsey, and with him Mrs. Watson, the housekeeper.

CHAPTER XII

ONE MYSTERY FOR ANOTHER

The most commonplace incident takes on a new appearance if the attendant circumstances are unusual.  There was no reason on earth why Mrs. Watson should not have carried a blanket down the east wing staircase, if she so desired.  But to take a blanket down at eleven o’clock at night, with every precaution as to noise, and, when discovered, to fling it at Halsey and bolt—­ Halsey’s word, and a good one—­into the grounds,—­this made the incident more than significant.

They moved slowly across the lawn and up the steps.  Halsey was talking quietly, and Mrs. Watson was looking down and listening.  She was a woman of a certain amount of dignity, most efficient, so far as I could see, although Liddy would have found fault if she dared.  But just now Mrs. Watson’s face was an enigma.  She was defiant, I think, under her mask of submission, and she still showed the effect of nervous shock.

“Mrs. Watson,” I said severely, “will you be so good as to explain this rather unusual occurrence?”

“I don’t think it so unusual, Miss Innes.”  Her voice was deep and very clear:  just now it was somewhat tremulous.  “I was taking a blanket down to Thomas, who is—­not well to-night, and I used this staircase, as being nearer the path to the lodge When—­ Mr. Innes called and then rushed at me, I—­I was alarmed, and flung the blanket at him.”

Halsey was examining the cut on his forehead in a small mirror on the wall.  It was not much of an injury, but it had bled freely, and his appearance was rather terrifying.