The scene opens on an estate where two people are horseback riding. Their conversation is interrupted when they discover a body. The case finds its way to Mr Keen for his brand of expertise.
As the wealthy man shares his case with Mr Keen, one suspect emerges, his fiancee. Mr Keen demands the truth, but promises to leave no stone unturned, including the possibility that the fiancee might actually be the guilty one. Mr Keen, and partner Mmike Clancey go to the estate to poke around for their own clues. During the interviews, shots ring out. It seems it’s just Mike Clancey, apprehending an aledged prowler. It’s just a family member, but it marks the beginning of some sneaky, suspicious behavior.
Mr Keen drops some subtle words that drags out more family secrets. Secrets about the background of the fiancee are brought to light that gives a new aspect to the case. It’s enough to shine the light of suspicion from the girl to others who have good reason for the murder.
Some new clues pop up that give Mr Keen the fuel he needs. He sets his theory into a motion to spring a trap to catch the killer, and expose the hard evidence he needs to make charges stick.
The plot twists just won’t stop coming, but in the end all the truth of the high society soap opera style story come out as the killer confesses.