“I suppose I have to include the pillows in the illustration,” Amy said to herself. “Chapter One starts with two pillows under his head. Now one of those pillows has been moved and has a wet saliva spot. The reader will assume this pillow was used to suffocate him–which was the case, of course.
“More than one suspect had the time to sneak up the stairs, do the deed and sneak back down. But there’s only one suspect whose story is contradicted by the physical evidence.”
Amy screwed up her face and sighed. “Maybe if I change the pattern of the rug. Maybe that will hide the vital clue.”