I measured out the forty minims from the bottle, and poured the laudanum into a medicine glass.  “Fill it till it is three parts full,” I said, and handed the glass to Miss Verinder.  I then directed Betteredge to lock up the medicine chest; informing him that I had done with it now.  A look of unutterable relief overspread the old servant’s countenance.  He had evidently suspected me of a medical design on his young lady!

After adding the water as I had directed, Miss Verinder seized a moment—­while Betteredge was locking the chest, and while Mr. Bruff was looking back to his papers—­and slyly kissed the rim of the medicine glass.  “When you give it to him,” said the charming girl, “give it to him on that side!”

I took the piece of crystal which was to represent the Diamond from my pocket, and gave it to her.

“You must have a hand in this, too,” I said.  “You must put it where you put the Moonstone last year.”

She led the way to the Indian cabinet, and put the mock Diamond into the drawer which the real Diamond had occupied on the birthday night.  Mr. Bruff witnessed this proceeding, under protest, as he had witnessed everything else.  But the strong dramatic interest which the experiment was now assuming, proved (to my great amusement) to be too much for Betteredge’s capacity of self restraint.  His hand trembled as he held the candle, and he whispered anxiously, “Are you sure, miss, it’s the right drawer?”

I led the way out again, with the laudanum and water in my hand.  At the door, I stopped to address a last word to Miss Verinder.

“Don’t be long in putting out the lights,” I said.

“I will put them out at once,” she answered.  “And I will wait in my bedroom, with only one candle alight.”

She closed the sitting-room door behind us.  Followed by Mr. Bruff and Betteredge, I went back to Mr. Blake’s room.

We found him moving restlessly from side to side of the bed, and wondering irritably whether he was to have the laudanum that night.  In the presence of the two witnesses, I gave him the dose, and shook up his pillows, and told him to lie down again quietly and wait.

His bed, provided with light chintz curtains, was placed, with the head against the wall of the room, so as to leave a good open space on either side of it.  On one side, I drew the curtains completely—­and in the part of the room thus screened from his view, I placed Mr. Bruff and Betteredge, to wait for the result.  At the bottom of the bed I half drew the curtains—­and placed my own chair at a little distance, so that I might let him see me or not see me, speak to me or not speak to me, just as the circumstances might direct.  Having already been informed that he always slept with a light in the room, I placed one of the two lighted candles on a little table at the head of the bed, where the glare of the light would not strike on his eyes.  The other candle I gave to Mr. Bruff; the light, in this instance, being subdued by the screen of the chintz curtains.  The window was open at the top, so as to ventilate the room.  The rain fell softly, the house was quiet.  It was twenty minutes past eleven, by my watch, when the preparations were completed, and I took my place on the chair set apart at the bottom of the bed.