Sir Mark Fleet is stabbed in full view of an audience while delivering a speech in front of a painting called "The Red Lady." Although it was possible for someone to hide behind the painting it is determined that no one was in the crammed space even though it was cleaned as if to obliterate footprints in the dust. It appears that it was impossible for anyone to have stabbed Sir Mark and yet he was killed. Later the body is taken from the bedroom prior to it being delivered to the coroner for an autopsy. It is found on a burning haystack. Why would someone steal the body and set it on fire?
Dr. Hailey starts to uncover a strange financial scheme that led to Sir Mark leaving a sizable legacy to a young woman who he barely knew. In trying to get to the bottom of this mess Hailey discovers that Sir Mark had recently consulted with a spiritualist. So Hailey himself visits the spiritualist under the pretense of contacting the spirit of Sir Mark to find out why he left the money to the girl. Through the medium he learns of yet another young woman who knew Sir Mark. No sooner has the information been divulged the medium is stabbed amid some typical contrived Wynne business and in chasing the intruder out of the séance room Hailey discovers the body of the butler also stabbed.
Before the novel is through two more people are killed -- one in a similar apparently impossible stabbing death. Faster moving than most earlier Wynne books, heavy on dialogue, but plods down a bit with all the rigmarole about the financial chicanery and the writing of the wills that were behind the motive for the deaths of Sir Mark and all the other victims. Still out of Wynne's high output of sometimes dreary, often humorless mystery novels this is definitely one of his best.