When searching for his sister in wartime Germany, the innocent young man is executed publicly as a spy, the commander of a military zeppelin turns against the Kaiser and takes an oath of allegiance to the revolutionary party for which his fiancee is an active recruiter. Organized under the symbol of the cross and fueled by the enthusiasm and dedication of the Commander’s fiancee, the new party grows steadily until its anti-autocratic sentiment has spread throughout the country. On a bombing mission, the zeppelin commander refuses to attack a British sea town and begs his crew to follow his lead and join his crusade for peace. They ignore his pleas and continue preparations for the raid, but rather than kill civilians, the Commander blows up the zeppelin in mid-air, destroying his crew and himself.