The hall door had slowly opened, and against the lamp-lit background we saw the tall figure of Professor Presbury. He was clad in his dressing-gown. As he stood outlined in the doorway he was erect but leaning forward with dangling arms, as when we saw him last.
Now he stepped forward into the drive, and an extraordinary change came over him. He sank down into a crouching position, and moved along upon his hands and feet, skipping every now and then as if he were overflowing with energy and vitality. He moved along the face of the house and then round the corner. As he disappeared Bennett slipped through the hall door and softly followed him.
"Come, Watson, come!" cried Holmes, and we stole as softly as we could through the bushes until we had gained a spot whence we could see the other
