A few months later she had made her way to Moscow where she was able to be reunited with her husband who had also managed to escape from Germany. Between August 1935 and July 1937 she attended the Comintern's International Lenin School in Moscow, where she was identified by the cover name "Hilde Engelmann". The two of them then made their way back to France. For many people it took some months for the declaration of war by France and England to have much obvious impact, but thousands of German refugees from Nazi Germany, including Lilli Herrmann-Ries, were identified as enemy aliens and arrested. She was held at the concentration camp in Gurs (with a short interval when she was held at Rivesalt) for sixteenth months. In June 1941 she was returned to Germany with her daughter and set to work at the steel works in Neunkirchen. However, on 21 September 1941 she was arrested by the Gestapo. At a trial on 28 May 1942 she was sentenced to spend four and a half years in prison. She was held in prison at Aichach in Upper Bavaria between 1942 and 1945. At the end of the war, in May 1945, she was released by US troops. Her husband, by this time, had died under circumstances that were never clear, in February 1944, at .