Fog and his sister, Night were given superhuman powers by the scientists of the Third Reich shortly after the Japanese invasion of Pearl Harbour. Night and Fog were intended to personify the figuartive "Night and Fog" into which Hitler decreed that all potential enemies of the Nazi's in conquered Western nations were to disappear. Night and Fog were thus sent on missions to capture or kill various opponents of the Nazi's.
Since September 1939, Irish - American steel magnate "Emerald Ed" Reilly had been trying to slow down production of ball bearings and other war materials for the Allies due to his hatred of the British. But his attitiude changed once the USA entered World War 2 and after he heard about the Nazi concentration camps and policies of mass murder, he co-operated with the Allies war effort.
Hitler sent Night and Fog to persuade Reilly to resume slowing down production. When he refused, Fog threw Reilly out of a window many stories above ground level. Reilly was caught by his daughter Danette in her Firebrand identity, but the strain on his heart due to his fall meant that "Emerald Ed" died in his daughter's arms.
Meanwhile Night and Fog were fighting members of the All Star Squadron, and despite the heroes' efforts, the pair escaped. It is not known wether they survied World War 2 or not.