German Navy, and the two British brothers enlist in the Royal Flying Corps. Monte gets a kiss from a girl at the recruiting station. When Roy finally introduces Monte to Helen, she invites Monte to her flat. Monte tries to rebuff her advances for his brother's sake but gives in. The next morning, however, he is for once ashamed of himself. Meanwhile, Karl is an officer aboard a Zeppelin airship sent to bomb Trafalgar Square, London. As the bombardier-observer, he is lowered below the clouds in a spy basket. He deliberately guides the Zeppelin over water, where the bombs have no effect. Four RFC fighters are sent to intercept the Zeppelin. Roy pilots one, with Monte as his gunner. To gain altitude and speed more quickly, the airship commander decides to sacrifice Karl by cutting the cable that secures his pod. When that is not enough, he orders everything possible to be jettisoned. He then accepts the advice of another officer; the officer and other crewmen obediently leap to their deaths "for Kaiser and fatherland." German machine gunners shoot down three aircraft; Roy and Monte survive a crash landing. After his machine guns jam or run out of ammunition, the last British pilot aloft dives his fighter into the dirigible, setting it ablaze. The brothers narrowly avoid being killed by the crashing Zeppelin. Later, Monte is branded a coward in France for shirking his duty when another pilot takes his place and is shot down. Roy and Monte step up when a staff colonel asks for two volunteers for a suicide mission. They are to destroy a vital enemy munitions depot. They will sneak in using a captured German bomber the next morning so that a British brigade will have a chance in their otherwise hopeless afternoon attack. Roy discovers a drunk Helen in a nightclub with Captain Redfield that night. When he tries to take her home, she turns on him, revealing that she never loved him, that she was, in fact, not the young innocent he believed her to be. Devastated, Roy joins Monte for some carousing. Monte decides not to go on the mission and nearly persuades Roy to do the same, but in the end, Roy drags Monte back to the airfield. They blow up the German munitions dump but get caught in the act by the Imperial German Flying Corps squadron nicknamed the Flying Circus