Andrew Wyke, a famous mystery writer, invited wife Marguerites lover, Milo Tindle, to his country house for the weekend.
Marguerite had lavish tastes and numerous lovers, but would not leave Andrew because none of her lovers could afford to maintain her lifestyle. Knowing that Milo, a self-made popular hairdresser from a poor Italian immigrant family, could barely afford Marguerites expenses at it is, Andrew decided to give him a large sum of money to take Marguerite off his hands.
Andrew came up with an insurance fraud scheme that will give Milo 170,000, the value of Marguerites most expensive jewels. Milo will play the burglar and steal Marguerites jewels, while Andrew used his talents as mystery write to plan out corresponding clues to fool the police and insurance company. Milo gets Marguerite, Andrew gets to stop paying her bills.
All went well, the two men had great fun playing out the plot, until ... (Since this is a thrilling mystery, to tell you more would ruin it.)