62 But she was awakened by a loud knocking. At first, since it was interwoven with the dream from which she was roused, she could not attach the sound to reality. The knocking went on and she was conscious that it must be at the gateway of the compound. It was quite dark. She had a watch with phosphorised hands and saw that it was half-past two. It must be Walter coming back—how late he was—and he could not awake the boy. The knocking went on, louder and louder, and in the silence of the night it was really not a little alarming. The knocking stopped and she heard the withdrawing of the heavy bolt. Walter had never come back so late. Poor thing, he must be tired out! She hoped he would have the sense to go straight to bed instead of working as usual in that laboratory of his. There was a

