The Agatha Christie Book Club

Does the mind grow duller with age, or does the mere actions of game playing, puzzle solving increase their sharpness? Two seniors, newly widowed wished to keep their 'little grey cells' active. By chance a neighbor appears to disappear, her character flaws seemed to lead them into believing that she could be a victim of something dangerous. They use what they have learned from their book club to find the answers, but when they do, who would believe them?
Many false clues, many possible characters had the right motives to commit a 'perfect' crime.