Stern fled Germany in December, 1937, reportedly carrying nothing but a small suitcase. He decided to join his sister at the gallery in London. Their plans to develop further were interrupted a few years later once the war began. Stern was interred as an enemy alien in a refugee camp on the Isle of Man for two years. The British government then allowed him to immigrate to Canada. Stern sailed on the Polish liner "Sobieski", but was unable to get his money and belongings out of Britain. He then spent two years in internment camps in New Brunswick and Quebec. He was given refugee status upon his arrival. He took steps to be exempted from this status, and made contact with the man who ran the Canadian Refugee Organization, William Birks, who immediately vouched for Stern.