After the "Anschluss" in March 1938, many of his relatives were arrested. At his mother's insistence, Bretholz fled on a train to Trier, Germany, where he was met by a smuggler. He swam across the Sauer River into Luxembourg, where he spent five nights in a Franciscan monastery. Bretholz was arrested two days later in a coffee shop and chose to be taken to the Belgian border over arrest or being sent back to Germany. On November 11, 1938 he arrived in Antwerp, Belgium, where he stayed for a peaceful eighteen months, and went to a public trade school to become an electrician as an alternative to being sent to an internment camp. During that time, Bretholz learned to speak Dutch. On May 9, 1940, he entered a hospital in Antwerp to have surgery on a hernia, but Antwerp was bombed the next morning before he could be operated on. Upon being discharged from the hospital, he was arrested as an enemy alien. Now that the war had reached Antwerp, being an Austrian – and thus, because of the "Anschluss", German – citizen, Bretholz became an enemy to Belgium. He was sent to St. Cyprien, an internment camp near the Spanish border. His friend Leon Osterreicher came to visit him and instructed him to escape by climbing under the camp's fence. While living with distant relatives nearby, he was sent to an assigned residence in Cauterets, France, near the Pyrenees Mountains, where he stayed for eight to ten months until on August 26, 1941, when the deportation began from this town. Upon a warning from the mayor of Luchon, he hid with his uncle overnight in the Pyrenees, returning the next day to find half of the ghetto's population deported. With his cousin Albert Hershkowitz he walked across the Swiss border in October 1942 under the name "Paul Meunier", only to be stopped by a Swiss mountain patrol and sent back to France. There he was sent to the Rivesaltes internment camp, where he remained for two weeks before being sent to Drancy, a large-scale deportation camp in the suburbs of Paris.