Six Minutes to Midnight (2020) on Netflix

Plot summary

The Augusta Victoria College in Bexhill-on-Sea takes in the daughters of Nazi Germany's most influential families, sent to England in the summer of 1939 to learn English and to speak for a National Socialist future. British intelligence keeps the school under watch. Wheatley, the English teacher, works as a government agent too, and when his cover breaks he vanishes before he can reach his handler, Colonel Smith. Another German-speaking agent, Thomas Miller, arrives to fill the teaching post. Miss Rocholl is the headmistress, and Ilse Keller, once a pupil there, teaches physical training. Miller sees the danger gathering and tries to alert the authorities, who treat him as the threat instead.