After the Nazis came to power she moved back to Berlin. On 20 July 1944 there was a plot to assassinate the leader which came close to success. Government authorities had already prepared a list of former politicians from the Weimar years to be rounded up in the event of intensified domestic opposition. The mass arrest was implemented on the night of 22/23 August 1944. There being no longer significant numbers of former Communist Party politicians at liberty in Germany, roughly 4,000 former officials and members of mainstream centre and left-wing "Bourgeois" parties were detained. Annemarie Oestreicher was one of them. Many of the detainees were released after a few weeks, but others, including Oestreicher, were taken to the Ravensbrück concentration camp. It was here, under circumstances that have never become clear, that she died, probably early in 1945.