About nine o'clock the light among the trees was extinguished, and all was dark in the direction of the Manor House. Two hours passed slowly away, and then, suddenly, just at the stroke of eleven, a single bright light shone out right in front of us.
"That is our signal," said Holmes, springing to his feet; "it comes from the middle window."
As we passed out he exchanged a few words with the landlord, explaining that we were going on a late visit to an acquaintance, and that it was possible that we might spend the night there. A moment later we were out on the dark road, a chill wind blowing in our faces, and one yellow light twinkling in front of us through the gloom to guide us on our sombre errand.
There was little difficulty in entering the grounds, for unrepaired breaches gaped in the old park wall. Making our way among the trees, we reached the lawn, crossed it, and were about to enter through the window when out from a clump of laurel bushes there darted what seemed to be a hideous and distorted child, who threw itself upon the grass with writhing limbs and then ran swiftly across the lawn into the darkness.
"My God!" I whispered; "did you see it?"
Holmes was for the moment as startled as I. His hand closed like a vice upon my wrist in his agitation. Then he broke into a low laugh and put his lips to my ear.
"It is a nice household," he murmured. "That is the baboon."
I had forgotten the strange pets which the doctor affected. There was a cheetah, too; perhaps we might find it upon our shoulders at any moment. I confess that I felt easier in my mind when, after following Holmes' example and slipping off my shoes, I found myself inside the bedroom. My companion noiselessly closed the shutters, moved the lamp onto the table, and cast his eyes round the room. All was as we had seen it in the daytime. Then creeping up to me and making a trumpet of his hand, he whispered into my ear again so gently that it was all that I could do to distinguish the words: "The least sound would be fatal to our plans."
I nodded to show that I had heard.
"We must sit without light. He would see it through the ventilator."
I nodded again.
"Do not go asleep; your very life may depend upon it. Have your pistol ready in case we should need it. I will sit on the side of the bed, and you in that chair."