Miss Wyckham was a German spy who posed as a schoolteacher.
Wyckham pretended to help the boys capture the Nazis in the church, but revealed that she was a double agent. She fled with Koenig and the other Nazis when George and Clyde took the Chronosteel from their weapon, a device for avoiding radar. The Nazis fled to the beach but were taken prisoner by the Home Guard. Given that the penalty for treason in Britain in 1943 was death, Miss Wyckham was most likely executed. (TV: Lost in Time)