Born in Shenandoah, Pennsylvania, Ciszek joined the Jesuits in 1928 and volunteered to serve in Russia. For that purpose he went to Poland, where he was stationed when it was invaded in 1939 by Germany and then by Russia. He ended up in the Siberian gulag, where he labored and ministered to prisoners. He was released in 1955, but remained in the Siberian city of Norilsk where he continued to offer the sacraments to the Catholics there. The KGB moved him out of Norilsk but he maintained his missionary activity in other parts of Russia until 1963, when he was exchanged for a Russian spy captured in the United States. Back in the U.S., he lived and worked at Fordham University.