Based on a lugubrious novel by Ludwig Wolff, The Mysterious Lady is a romance/espionage tailored to the talents of Greta Garbo. The divine Miss G plays an alluring Russian spy, directly answerable to satanic-featured general Gustav von Seyffertitz. While she's accustomed to fomenting suicides and apoplexy amongst her male victims, Garbo cannot help but become romantically involved with Austrian-officer Conrad Nagel. Forced to choose between her love of Russia and her love for Nagel, Garbo decides upon the latter--meaning that there's a bullet in the future for vonSeyfertitz. For all its MGM gloss, Mysterious Lady would be just so much borscht without the ethereal presence of its female star.
by Hal Erickson synopsis