Mr. Grex of Monte Carlo

In order to realign France with Germany and Russia and cause political strife with England, a Russian diplomat plans a rendezvous with two colleagues in Monte Carlo.

Posing as a gambler named Mr. Grex, the duke arrives in Monte Carlo with his daughter Feodora and arranges to meet his conspirators for the signing of a secret treaty.

In the meantime, Feodora is courted ardently by Richard Lane, a rich American who refuses to be rejected.

Add a British spy, excitement on land and sea, plots within plots, and a dash of romance to make one of Oppenheim's best thrillers.