Theodore Eckertz was re-arrested in 1939. Maria Eckertz took work as a bookkeeper. She was re-arrested in August 1944, during the course of a mass round up of people with records of left-wing political activity, which came in the wake of a failed assassination attempt against the leader, and taken to Ravensbrück concentration camp. On 25 April 1945 she was able to join a "transport" of 4,000 Polish Ravensbrück inmates, transferred in Red Cross buses to Sweden on the basis of the larger deal struck between Count Bernadotte and the government of the crumbling Nazi state. The transfer to Sweden enabled her to survive the concentration camp.