Professor Sarah Deane's crotchety Aunt Julia ends up in the hospital following a heart attack and becomes the only witness that may be able to identify whomever murdered an emergency room patient. Sarah's husband, Dr MacKenzie is her aunt's doctor. The night after her bypass surgery Julia is nearly murdered herself, but everyone tells her it was just a bad dream, a result of anesthesia and surgery. Julia has to defend herself when even Sarah and her doctor don't believe her. It takes another patient's death to convince all that a killer is loose. I really liked this book in the series, a change from the usual academia setting. I never did guess the killer so that makes it a really good mystery to me.