During a strike at the Paterson, New Jersey, silk mills, John King falls under the spell of Bolshevist agitator Sophia Guerni. When Guerni and her confederate Boris Blotchi decide that their next target will be the peaceful strike at the Weston shipyards, John assents, although his childhood sweetheart May Weston runs the plant and also supports John's poverty-stricken father, Dr. King. However, when John overhears his cohorts extorting money from May, he intervenes and is seriously wounded. After subduing John, the agitators bomb the plant where May and Dr. King have taken refuge. Shaken by the violence, John drives back the mob and renounces his revolutionary doctrine. May then forgives him and the two are happily reunited.