Margaretha Geertruida Zelle (1876 – 1917), better known by the stage name Mata Hari, was a Dutch exotic dancer who was convicted of being a spy and executed by firing squad in France during the first World War.

Sir Basil Home Thomson, KCB (1861 – 1939) was a British intelligence officer, police officer, prison governor, colonial administrator, and writer. Thomson interviewed Mata Hari in London in 1915 as part of a British investigation into her espionage activities.

This is his first hand account of that meeting. He also recounts the interrogation of other female foreign spies during his period in office.