Adapted from a play by Victor Sardou, Diplomacy was another collaboration between actress Blanche Sweet and her then-husband Marshall Neisan. Most of the action takes place along the Riviera, where heroine Dora de Zares (Sweet) comports herself in a most mysterious fashion. The audience is encouraged to think that Dora is a spy of some sort or other, especially when a packet of important diplomatic papers is stolen from her husband Julian Wentworth (Neil Hamilton). But there's plenty of intrigue and surprises before the plot is explained and the truth is revealed. Viewers in 1926 were advised to keep their eyes on "silly ass" Englishman Robert Lowry (Matt Moore), who like Dora wasn't all that he seemed to be.
by Hal Erickson synopsis