Glamorous Ruth Van Rydock (Joan Collins) is convinced her sister Carrie Louise is in danger, and confesses her suspicion to Miss Marple over tea. Carrie Louise, a quirky philanthropist with a string of ex-husbands, runs a correctional facility for young men on her estate. Miss Marple arrives to make some gentle inquiries and finds chilling danger lurking surprisingly close to home. When murder is the real-life plot twist during an amateur theater rehearsal on the estate, Miss Marple has to separate theatrical tricks from reality in an attempt to save Carrie Louise from the dire final act that awaits her.