After the annexation of Czechoslovak borderlands, Herbert briefly fled to Prague, probably helping to organize the escape of his sister and her husband to Hradec Králové. However, he returned to Ústí nad Labem himself, and was arrested in November 1938. Another, mandatory, name was added to his name, henceforth he was to be called Herbert Israel Heller. All his official documents were marked with a red letter J. According to Nazi laws, he was a Jew, as was his entire family.
Herbert Heller's residence card. Regional Museum in Ústí nad Labem.
Hilda, a German Catholic, refused to divorce Herbert. She persistently intervened with the authorities and finally achieved his release from prison, after which he was arrested again and placed in the Oranienburg (Sachsenhausen) concentration camp.
Hilda continued to protest at the authorities. On May 15, 1939, Herbert Heller was released on the basis of his wife's repeated interventions and received the legal status of an "Aryanized Jew" (""Arisch versippt” in German), valid until the end of his marriage. It was only thanks to Hilda's loyalty that he was not deported to death.
He earned a living as a laborer, a concrete worker, and a railway construction worker. In 1944, he was assigned to forced labor in Haigen in Westphalia, from where he escaped with false documents at the end of the war and hid in Jetřichovice.