On November 5, 1942, Bretholz was deported on convoy 42 with 1000 others headed for Auschwitz. With his friend Manfred Silberwasser he escaped through the window and leaped off the train. Staying with two priests on subsequent nights, he and Manfred were given train tickets to Paris with a new set of false identification papers, this time under the name "Marcel Dumont". Upon crossing into the Southern region (Vichy France), he was arrested again for abandoning his assigned residence. He spent nine months in prison, one month of which was in solitary confinement for having escaped for two days. He was released in September 1943, and was then sent to Septfonds labor camp for one month.