Antonia is haunted by a secret. Charles will soon be asking questions and she fears the answers will be devastating for their marriage. With her own guilt weighing heavily on her mind, Antonia and Charles encounter the savage murder of frail, elderly Catherine Bacon. Though the killing is blamed on a passing dustman, Lord and Lady Danvers begin tracking clues through Victorian Canterbury. What they find leads to a shocking revelation and a chase scene across the rooftop of Canterbury Cathedral.