Private investigators Psychological fiction Murder Nineteen thirties Disinheritance Mystery fiction Police Women authors Large type books Missing persons Nineteen twenties Waterhouse, Simon (Fictitious character) Zailer, Charlie (Fictitious character) Aristocracy (Social class) Children Coincidence Crimes against Fiancées Friendship Investigation Officials and employees Poirot, Hercule (Fictitious character) Railroad travel Suspense fiction Age determination Conduct of life Criminal investigation Female friendship Forgiveness Impersonation