Consequently, many of the cooperating institutions were Catholic boarding schools, usually operating within the walls of convents or monasteries. Dom Bruno would personally accompany "his children" to their new homes or move them to new locations to prevent suspicion among villagers. He would frequently visit these children, providing a link with their parents who were also hiding, when not deported as was often the case. In addition to building and running his "underground railroad", Dom Bruno ensured that his charges were provided with false identification, including non-Jewish sounding names, and fake ration cards, as well as financial assistance to the rescuers. These logistical concerns could only be met with the willing but risky cooperation of numerous city officials, civil servants, and generous donors. The Gestapo got wind of Father Bruno's activities and raided Mont César Abbey in 1944. Fortunately, Dom Bruno was away at the time. Following the unsuccessful raid, the monk went into hiding himself, trading his habit for civilian garb and sporting a beret to hide his tonsure. A fellow monk at the abbey provided him with several skillfully forged identification cards. Often using a bicycle and in spite of subsequent close calls, Dom Bruno continued his dangerous mission of mercy for the duration of the Nazi occupation. Following the liberation of Belgium in September 1944, Dom Bruno assisted in reuniting the children with their parents or other members of their immediate family. Problems arose when representatives of the Jewish community opposed attempts by some Christians to adopt orphaned Jewish children, especially since many of these children requested baptism as the result of their Catholic experience. During the Nazi occupation, Dom Bruno opposed active conversion of his charges, but afterward took the position that each case should be evaluated individually with the best interest of the child being the deciding factor. As the war against Germany was still in progress, Dom Bruno rejoined the Belgian armed forces as a chaplain. At war's end, he briefly returned to Mont-César, but was reassigned by his order to perform pastoral and educational work at other locations in Belgium, France and Rome. No longer burdened by his wartime self-imposed rescue mission, Dom Bruno resumed his studies of Saint Irenaeus' legacy and in 1954 published the definitive lexicon on the subject. Attracted by the ecumenical spirit of Chevetogne Abbey, where, as a young priest, he had become a disciple of Dom Lambert Beauduin, Dom Bruno had, over the years, requested a release from the Mont-César community in order to join the monks at Chevetogne.