1) After Pauline Stacey's fall, Father Brown proves the sun‑prophet Kalon murdered her by exploiting her hereditary blindness, while Joan Stacey's manipulation of the will supplied a secondary motive.
2) Investigating Sir Arthur St. Clare's legend, Brown reconstructs that St. Clare killed Major Murray to hide corruption, fomented a needless slaughter to bury the crime, and was later executed by his own men while history sanctified him.
3) In Sir Aaron Armstrong's death Brown shows it was a suicidal episode misread as murder: a chaotic rescue involving shots, a rope and a knife accidentally precipitated the fatal fall, exonerating Patrick Royce.
Former criminal Flambeau, now retired in Spain, receives Father Brown and a series of visitors whose intrigues yield several puzzling murders and thefts.
Father Brown’s method—moral-intuitive immersion in a suspect’s mind to reconstruct motive and opportunity—resolves each case and frames a wider argument about remorse, repentance and the limits of scientific criminology.
The volume closes with Flambeau’s frank confession of his past and a sustained plea for humane understanding and forgiveness.
Father Brown recounts how Prince Otto, hunting for hidden gold, was stealthily gagged with his own military sash at a hermitage; mute and fleeing, he was then killed by a palace sentry (Schwartz), whose rescuer Hedwig later married. Brown, calling the affair a grim fairy-tale, lingers on the suspected double treachery of the Chamberlain.