In 1917, France is embroiled in World War I. Dubois, head of the French spy bureau, offers to spare the life of a captured agent (an uncredited Mischa Auer) if he will reveal who he is protecting.

Dubois suspects it is Mata Hari, a celebrated exotic dancer, but the prisoner chooses execution by firing squad.

Lieutenant Alexis Rosanoff of the Imperial Russian Air Force lands in Paris after a dangerous flight over enemy territory, bringing important dispatches from Russia.

Mata Hari goes into hiding, but when Andriani informs her that Rosanoff crashed and was seriously injured on his way back to Russia, she defies him and resigns to go to her love.

However, when Dubois threatens to have Rosanoff brought in to testify that he met her outside Shubin's office just after the murder, Mata Hari gives up.

[5] As with many pre-Code Hollywood films, Mata Hari was censored upon its reissue after strict enforcement of the Hays Code began in mid-1934.

According to online reports, not officially confirmed but for more than ten years apparently never contradicted, a print of the original uncut version, subtitled in French and Dutch, survives at the Cinémathèque Royale de Belgique in Brussels, where it was publicly shown in 2005.

[11][12] That institution's program guide for March 2009 documents a showing of Mata Hari with a stated running time of 92 minutes.