Beatrice Wilhelmina Marie Albertina (Trix) Terwindt (27 February 1911 – 7 April 1987) was a member of the Dutch resistance during World War II.

Terwindt suffered from mental and physical problems as a result of her two years imprisonment in concentration camps and was a long-term advocate for treatment of former prisoners for survivor syndrome.

At the end of August 1939, Terwindt worked on the last KLM flight to Germany before the outbreak of World War II [1] With the invasion and occupation by the Germans in World War II, Terwindt worked in The Hague, assisting refugees from the bombing of Rotterdam.

She was recruited to work for MI9 by Donald Darling, MI9's representative in the Iberian Peninsula, who arranged for her to fly to England.

[2] Downed airmen were usually guided through German-occupied countries to Spain, a highly dangerous clandestine activity arranged by escape and evasion lines.

Neave sent Terwindt for training to the Special Operations Executive (SOE) which was infiltrating agents and saboteurs into the Netherlands.

She would work by herself, although Neave gave her a few names of contacts and from her previous experience she knew many people in the country.

She later told Neave that she played a game of "cat and mouse" with the Germans, revealing nothing of her mission or her contacts.

[8] However, she was transferred to Ravensbrück concentration camp for women as a Nacht und Nebel prisoner to be treated with more than ordinary severity.

[1] Terwindt went back to work as chief stewardess for KLM, but left the job in 1949 because of ill health.

After his death, she had a mental disorder and was treated by Jan Bastiaans, a specialist in survivor syndrome whose controversial treatments included LSD.