During World War I, a morphine-addicted female German super-spy known as “Fraülein Doktor” (Suzy Kendall) seduces a laundryman to find out which ship the redoubtable British military leader Lord Kitchener will be sailing on to Russia, and when it will sail.
She then helps a German U-boat to sink HMS Hampshire outside Scapa Flow with Kitchener on it, taking him and 700 more victims to a watery death.
Her unsavoury past is examined by British intelligence officer Colonel Foreman (Kenneth More), who sends Meyer (James Booth) to Germany to kill the dangerous woman.
Meanwhile, Fraülein Doktor forms an association with Dr Saforet (Capucine), a lesbian French scientist and the creator of a deadly new mustard gas formula.
After murdering Dr Saforet, she steals the formula and turns it over to the Germans, who use it with devastating results against the Allies in the trenches.
Meyer tracks down Fraülein Doktor and prepares to kill her, an act now sanctioned by the Germans, who have no more use for their drug-addicted spy. Instead, he falls in love with her, and the Germans merely stage her death.
She later turns up in Spain impersonating a Contessa who is arranging a Red Cross train to aid Allied wounded. In reality, she and other German spies are out to steal Allied defence plans for a German attack in Belgium.
She is discovered by Colonel Foreman, but he is dispatched by Meyer. Finally, when Meyer is killed by the Germans, Fraülein Doktor laughs like a maniac, then breaks into hysterical sobbing, realising the slaughter she has brought about.
The nightmarish climactic battlefield scenes depicting the horror of a mustard gas slaughter – with German cavalry emerging through the gas cloud on horses who are wearing protective clothing and gas masks while thousands of men are shown dying horrible deaths – will stay with you.
This Italian and Yugoslav co-production was loosely based on the life of Elsbeth Schragmüller, a German Ph.D who operated a school for spies in Antwerp during WW I.
Marchioness de Haro
Dona Elena de Rivas
Sgt. Otto Latemar
General von Ludendorff
Lt. Wilhelm von Oberdorff
Bernard De Vries