Who killed Prince Michael? Queen Varaga, disguised as Mademoiselle Brun, shoots him when he unexpectedly recognizes her in the Council Chamber. She later plants the pistol in Isaacstein's luggage and manipulates the returned letters so the authorities will solve the diamond cipher for her.
Who is King Victor? The man posing as Monsieur Lemoine. King Victor kidnapped the genuine Sûreté detective, assumed his identity, and used the investigation to direct suspicion while waiting for the diamond's hiding place to be exposed.
Why is Mademoiselle Brun important? The woman at Chimneys is not the governess employed by the Comtesse de Breteuil. She is Queen Varaga, believed killed in the Herzoslovakian revolution, and she is working with King Victor to recover the stone.
Where is the diamond? The cipher does not lead to the library, and it has nothing to do with the Earl of Richmond's portrait. "Richmond seven straight eight left three right" counts from a rose named Richmond in the rose garden, where Angèle Mory buried the wrapped jewel. Anthony invents the library solution to lure Varaga into a watched room.
Who is Anthony Cade? Anthony is Prince Nicholas Obolovitch, who circulated the report of his own death so he could live without his title. Prince Michael's death makes him the principal legitimate claimant, and he ultimately agrees to return and rule Herzoslovakia.
What happens to Anthony and Virginia? They marry before the final gathering. Virginia accepts the prospect of becoming queen, while Anthony accepts the 'regular work' of kingship because a settled public role makes a life with her possible.
What happened to the memoirs? Anthony never gives the genuine manuscript to the false Mr. Holmes. He places a dummy packet in circulation, keeps the original safe, and finally sends Jimmy to deliver it and collect the promised payment.
Themes and What the Ending Means
Identity as performance Anthony, King Victor, Queen Varaga, and even Virginia survive by controlling what others think they are. The mystery repeatedly turns on the difference between a convincing social role and a verifiable identity.
Adventure versus duty Anthony values mobility and risk, but his romance with Virginia forces him to reconsider permanent responsibility. The throne is less a reward than the price of the life he chooses.
Politics as theater George's grand language, the royalist delegation's ceremony, and the hidden bargaining over oil show public ideals continually sharing space with private interests.
Observation and misdirection Battle notices behavior without announcing conclusions, whereas the false Lemoine loudly manufactures a case. The contrast separates genuine detection from the performance of detection.
The country house as national property Chimneys is both a family home and an unofficial stage for state business. Lord Caterham's comic resentment underlines how public demands repeatedly invade private space.