Diana of Kara-Kara by Edgar Wallace

Diana stirred uneasily in her sleep and woke. There was no sound but the distant snore of Mr. Superbus, but she had an uncanny instinct that all was not well. Slipping out of bed, she pulled on her dressing-gown and looked out of the window. She saw a figure on the sidewalk. A man, slight of build, round-shouldered. She saw him clearly in the light of the street standard which was immediately opposite the house. She guessed his face rather than saw it, and wondered where she had seen him before. Stark, the window-cleaner! Now she knew him. As she looked, he stood back quickly, bringing himself against the railings. Craning her neck, she saw a shadowy policeman slowly passing the end of the street. He reached the opposite corner and stopped, came a few steps down Cheynel Gardens and stopped again. There was the flare of a match. It was the hour when policemen produce surreptitious pipes in defiance of all regulations. The figure against the railings remained motionless.

"What do you want? " demanded Diana.