In 1945 Ole Lippman, leader of the Danish section of the Special Operations Executive, invited the British Royal Air Force to assist their operations by attacking Nazi headquarters in Copenhagen. Accordingly, air vice-marshal Sir Basil Embry drew up plans for a spectacular precision attack on the Sicherheitsdienst and Gestapo building, the former offices of the Shell Oil Company. Political prisoners were kept in the attic to prevent an air raid, so the RAF had to bomb the lower levels of the building.