Rudolph Klein, a German spy, tries to persuade his brother Herman, a trusted employee of the Spencer Steel Works, to blow up the munitions factory. When World War I breaks out, Spencer's son Graham decides to enlist in the army, but when his mother Natalie, a cold-hearted social butterfly, objects, he wavers in his decision. Rudolph persuades Herman that Graham is trying to seduce his daughter Anna, and, for revenge, Herman finally agrees to blow up the plant. Anna overhears the conspiracy and rushes to warn the Spencers, but gets caught in the explosion instead. Her death cements Graham's resolution to enlist and he goes off to war. Natalie then decides to leave Spencer, freeing him for Audrey Valentine, a widow who has lost her son at the front.