The Valley of Ghosts by Edgar Wallace

'Who was the woman in Mr Merrivan's room? The butler of the deceased man heard a woman's voice distinctly. Mr Merrivan had received no visitors that evening. The butler had admitted nobody, and yet, coming downstairs half an hour after Mr Merrivan had told him to go to bed, he heard the sound of voices, and one of those voices was a woman's. Who was this mysterious visitor? In all probability she can throw a light upon a double crime, which in its sensational features has no parallel in recent years.'

Andy read the newspaper leader calmly. There were others very similarly worded. The reporters had got to the butler. That was inevitable. He couldn't keep the man locked up, and apparently the warning he had delivered had had no effect. The first reporter he saw the next morning brought the incident of the woman forward as being of supreme importance. "Possibly," said Andy, "she might tell us something, but obviously she could not throw any light on the murder. She was seen leaving the house at eleven o'clock. The murder was not committed until past one."